From 021d6072825ff94ce7fe0bd40e8414af62fac33d Mon Sep 17 00:00:00 2001
From: Ed Santiago <santiago@redhat.com>
Date: Fri, 5 Apr 2019 09:59:54 -0600
Subject: [PATCH] rename 'is' to 'expect_output'

...and make the "$output" argument implicit, as well as the
description text. This greatly simplifies its invocation.

Also: make it test for exact matches unless --substring
option is passed; this eases my mind about a few potentially
ambiguous situations such as the one in #1464.

Also: add comments to two truth-table check functions

Also: reorder some config checks alphabetically, for ease
of reading.

Thanks to Tom Sweeney for the suggestions and encouragement.

Signed-off-by: Ed Santiago <santiago@redhat.com>

Closes: #1492
Approved by: rhatdan
---
 tests/basic.bats      |   2 +-
 tests/bud.bats        | 174 +++++++++++++++++++++---------------------
 tests/commit.bats     |   6 +-
 tests/config.bats     |  27 +++----
 tests/from.bats       |  20 ++---
 tests/helpers.bash    |  55 +++++++++----
 tests/images.bats     |   8 +-
 tests/mount.bats      |   6 +-
 tests/namespaces.bats |   8 +-
 tests/pull.bats       |  24 +++---
 tests/push.bats       |   2 +-
 tests/registries.bats |   2 +-
 tests/rename.bats     |   8 +-
 tests/rm.bats         |   8 +-
 tests/rmi.bats        |  24 +++---
 tests/run.bats        |  68 ++++++++---------
 tests/secrets.bats    |   4 +-
 tests/selinux.bats    |   8 +-
 tests/squash.bats     |   3 +-
 19 files changed, 243 insertions(+), 214 deletions(-)

diff --git a/tests/basic.bats b/tests/basic.bats
index 9e8a6bfb3f7..d256b518e33 100644
--- a/tests/basic.bats
+++ b/tests/basic.bats
@@ -106,5 +106,5 @@ load helpers
   [ "$output" != "" ]
   run_buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "output from buildah images -q"
+  expect_output ""
 }
diff --git a/tests/bud.bats b/tests/bud.bats
index d3cf182635d..8ae2f0f8e25 100644
--- a/tests/bud.bats
+++ b/tests/bud.bats
@@ -44,9 +44,9 @@ load helpers
   run_buildah --debug=false images -a
   expect_line_count 8
   run_buildah --debug=false  inspect --format "{{index .Docker.ContainerConfig.Env 1}}" test2
-  is "$output" "foo=bar" "ContainerConfig.Env"
+  expect_output "foo=bar"
   run_buildah --debug=false inspect --format "{{.Docker.ContainerConfig.ExposedPorts}}" test2
-  is "$output" "map[8080/tcp:{}]" "ContainerConfig.ExposedPorts"
+  expect_output "map[8080/tcp:{}]"
 
   buildah bud --signature-policy ${TESTSDIR}/policy.json --layers -t test3 -f Dockerfile.2 ${TESTDIR}/use-layers
   run_buildah --debug=false images -a
@@ -180,7 +180,7 @@ load helpers
 
 @test "bud --layers with non-existent/down registry" {
   run_buildah 1 bud --signature-policy ${TESTSDIR}/policy.json --force-rm --layers -t test1 -f Dockerfile.non-existent-registry ${TESTSDIR}/bud/use-layers
-  is "$output" ".*no such host" "expecting non-existent-registry"
+  expect_output --substring "no such host"
 }
 
 @test "bud from base image should have base image ENV also" {
@@ -189,9 +189,9 @@ load helpers
   buildah config --env random=hello,goodbye ${cid}
   buildah commit --signature-policy ${TESTSDIR}/policy.json ${cid} test1
   run_buildah --debug=false inspect --format '{{index .Docker.ContainerConfig.Env 1}}' test1
-  is "$output" "foo=bar" "image environment, index 1"
+  expect_output "foo=bar"
   run_buildah --debug=false inspect --format '{{index .Docker.ContainerConfig.Env 2}}' test1
-  is "$output" "random=hello,goodbye" "image environment, index 2"
+  expect_output "random=hello,goodbye"
   buildah rm ${cid}
   buildah rmi -a -f
 }
@@ -203,7 +203,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "output from buildah images"
+  expect_output ""
 }
 
 @test "bud-from-scratch-iid" {
@@ -214,14 +214,14 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-from-scratch-label" {
   target=scratch-image
   buildah bud --label "test=label" --signature-policy ${TESTSDIR}/policy.json -t ${target} ${TESTSDIR}/bud/from-scratch
   run_buildah --debug=false inspect --format '{{printf "%q" .Docker.Config.Labels}}' ${target}
-  is "$output" 'map["test":"label"]' "buildah inspect"
+  expect_output 'map["test":"label"]'
 
   buildah rmi ${target}
 }
@@ -230,7 +230,7 @@ load helpers
   target=scratch-image
   buildah bud --annotation "test=annotation1,annotation2=z" --signature-policy ${TESTSDIR}/policy.json -t ${target} ${TESTSDIR}/bud/from-scratch
   run_buildah --debug=false inspect --format '{{printf "%q" .ImageAnnotations}}' ${target}
-  is "$output" 'map["test":"annotation1,annotation2=z"]' "buildah inspect"
+  expect_output 'map["test":"annotation1,annotation2=z"]'
   buildah rmi ${target}
 }
 
@@ -247,7 +247,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output"  "" "buildah images -q"
+  expect_output ""
 
   target=alpine-image
   buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile1.alpine -f Dockerfile2.nofrom ${TESTSDIR}/bud/from-multiple-files
@@ -261,7 +261,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-from-multiple-files-two-froms" {
@@ -279,7 +279,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 
   target=alpine-image
   buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile1.alpine -f Dockerfile2.withfrom ${TESTSDIR}/bud/from-multiple-files
@@ -296,7 +296,7 @@ load helpers
   buildah rmi -a
   run_buildah --debug=false images -q
   echo "$output"
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-multi-stage-builds" {
@@ -310,7 +310,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 
   target=multi-stage-name
   buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile.name ${TESTSDIR}/bud/multi-stage-builds
@@ -322,7 +322,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 
   target=multi-stage-mixed
   buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/multi-stage-builds/Dockerfile.mixed ${TESTSDIR}/bud/multi-stage-builds
@@ -334,7 +334,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-multi-stage-builds-small-as" {
@@ -348,7 +348,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 
   target=multi-stage-name
   buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile.name ${TESTSDIR}/bud/multi-stage-builds-small-as
@@ -360,7 +360,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 
   target=multi-stage-mixed
   buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/multi-stage-builds-small-as/Dockerfile.mixed ${TESTSDIR}/bud/multi-stage-builds-small-as
@@ -372,7 +372,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-preserve-subvolumes" {
@@ -395,7 +395,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-http-Dockerfile" {
@@ -407,7 +407,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-http-context-with-Dockerfile" {
@@ -419,7 +419,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-http-context-dir-with-Dockerfile-pre" {
@@ -431,7 +431,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-http-context-dir-with-Dockerfile-post" {
@@ -443,7 +443,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-git-context" {
@@ -462,7 +462,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-github-context" {
@@ -475,7 +475,7 @@ load helpers
   buildah --debug=false images -q
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-additional-tags" {
@@ -492,7 +492,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi -f $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-volume-perms" {
@@ -513,7 +513,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-from-glob" {
@@ -526,43 +526,43 @@ load helpers
   buildah rm ${cid}
   buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-maintainer" {
   target=alpine-image
   buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} ${TESTSDIR}/bud/maintainer
   run_buildah --debug=false inspect --type=image --format '{{.Docker.Author}}' ${target}
-  is "$output" "kilroy" "buildah inspect - .Docker.Author"
+  expect_output "kilroy"
   run_buildah --debug=false inspect --type=image --format '{{.OCIv1.Author}}' ${target}
-  is "$output" "kilroy" "buildah inspect - .OCIv1.Author"
+  expect_output "kilroy"
   buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-unrecognized-instruction" {
   target=alpine-image
   run_buildah 1 bud --signature-policy ${TESTSDIR}/policy.json -t ${target} ${TESTSDIR}/bud/unrecognized
-  is "$output" ".*BOGUS" "buildah bud - unrecognized"
+  expect_output --substring "BOGUS"
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud-shell" {
   target=alpine-image
   buildah bud --format docker --signature-policy ${TESTSDIR}/policy.json -t ${target} ${TESTSDIR}/bud/shell
   run_buildah --debug=false inspect --type=image --format '{{printf "%q" .Docker.Config.Shell}}' ${target}
-  is "$output" '["/bin/sh" "-c"]' ".Docker.Config.Shell (original)"
+  expect_output '["/bin/sh" "-c"]' ".Docker.Config.Shell (original)"
   ctr=$(buildah from --signature-policy ${TESTSDIR}/policy.json ${target})
   run_buildah --debug=false config --shell "/bin/bash -c" ${ctr}
   run_buildah --debug=false inspect --type=container --format '{{printf "%q" .Docker.Config.Shell}}' ${ctr}
-  is "$output" '["/bin/bash" "-c"]' ".Docker.Config.Shell (changed)"
+  expect_output '["/bin/bash" "-c"]' ".Docker.Config.Shell (changed)"
   buildah rm ${ctr}
   buildah rmi -a
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud with symlinks" {
@@ -636,7 +636,7 @@ load helpers
 @test "bud with ENTRYPOINT and RUN" {
   target=alpine-image
   run_buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile.entrypoint-run ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*unique.test.string" "buildah bud run-scenarios"
+  expect_output --substring "unique.test.string"
   cid=$(buildah from --signature-policy ${TESTSDIR}/policy.json ${target})
   buildah rm ${cid}
   buildah rmi ${target}
@@ -645,13 +645,13 @@ load helpers
 @test "bud with ENTRYPOINT and empty RUN" {
   target=alpine-image
   run_buildah 1 bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile.entrypoint-empty-run ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*error building at step" "buildah bud output"
+  expect_output --substring "error building at step"
 }
 
 @test "bud with CMD and RUN" {
   target=alpine-image
   run_buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/run-scenarios/Dockerfile.cmd-run ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*unique.test.string" "buildah bud output"
+  expect_output --substring "unique.test.string"
   cid=$(buildah from --signature-policy ${TESTSDIR}/policy.json ${target})
   buildah rm ${cid}
   buildah rmi ${target}
@@ -660,13 +660,13 @@ load helpers
 @test "bud with CMD and empty RUN" {
   target=alpine-image
   run_buildah 1 bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile.cmd-empty-run ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*error building at step" "buildah bud output"
+  expect_output --substring "error building at step"
 }
 
 @test "bud with ENTRYPOINT, CMD and RUN" {
   target=alpine-image
   run_buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/run-scenarios/Dockerfile.entrypoint-cmd-run ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*unique.test.string" "buildah bud output"
+  expect_output --substring "unique.test.string"
   cid=$(buildah from --signature-policy ${TESTSDIR}/policy.json ${target})
   buildah rm ${cid}
   buildah rmi ${target}
@@ -675,14 +675,14 @@ load helpers
 @test "bud with ENTRYPOINT, CMD and empty RUN" {
   target=alpine-image
   run_buildah 1 bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/run-scenarios/Dockerfile.entrypoint-cmd-empty-run ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*error building at step" "buildah bud output"
+  expect_output --substring "error building at step"
 }
 
 # Determines if a variable set with ENV is available to following commands in the Dockerfile
 @test "bud access ENV variable defined in same source file" {
   target=env-image
   run_buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/env/Dockerfile.env-same-file ${TESTSDIR}/bud/env
-  is "$output" ".*:unique.test.string:" "buildah bud output"
+  expect_output --substring ":unique.test.string:"
   cid=$(buildah from --signature-policy ${TESTSDIR}/policy.json ${target})
   buildah rm ${cid}
   buildah rmi ${target}
@@ -694,7 +694,7 @@ load helpers
   target=env-image
   run_buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${from_target} -f ${TESTSDIR}/bud/env/Dockerfile.env-same-file ${TESTSDIR}/bud/env
   run_buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/env/Dockerfile.env-from-image ${TESTSDIR}/bud/env
-  is "$output" ".*@unique.test.string@" "buildah bud output"
+  expect_output --substring "@unique.test.string@"
   from_cid=$(buildah from ${from_target})
   cid=$(buildah from ${target})
   buildah rm ${from_cid} ${cid}
@@ -750,7 +750,7 @@ load helpers
 @test "bud with --cpu-shares flag, invalid argument" {
   target=bud-flag
   run_buildah 1 bud --cpu-shares bogus --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/from-scratch/Dockerfile ${TESTSDIR}/bud/from-scratch
-  is "$output" ".*invalid argument \"bogus\" for " "buildah bud output"
+  expect_output --substring "invalid argument \"bogus\" for "
 }
 
 @test "bud with --cpu-shares flag, valid argument" {
@@ -769,7 +769,7 @@ load helpers
 @test "bud with --cpu-shares short flag (-c), invalid argument" {
   target=bud-flag
   run_buildah 1 bud -c bogus --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/from-scratch/Dockerfile ${TESTSDIR}/bud/from-scratch
-  is "$output" "invalid argument \"bogus\" for " "buildah bud output"
+  expect_output --substring "invalid argument \"bogus\" for "
 }
 
 @test "bud with --cpu-shares short flag (-c), valid argument" {
@@ -784,7 +784,7 @@ load helpers
   target=onbuild
   buildah bud --format docker --signature-policy ${TESTSDIR}/policy.json -t ${target} ${TESTSDIR}/bud/onbuild
   run_buildah --debug=false inspect --format '{{printf "%q" .Docker.Config.OnBuild}}' ${target}
-  is "$output" '["RUN touch /onbuild1" "RUN touch /onbuild2"]' ".Config.OnBuild"
+  expect_output '["RUN touch /onbuild1" "RUN touch /onbuild2"]'
   cid=$(buildah from ${target})
   root=$(buildah mount ${cid})
   run ls ${root}/onbuild1 ${root}/onbuild2
@@ -796,7 +796,7 @@ load helpers
   target=onbuild-image2
   buildah bud --format docker --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile1 ${TESTSDIR}/bud/onbuild
   run_buildah --debug=false inspect --format '{{printf "%q" .Docker.Config.OnBuild}}' ${target}
-  is "$output" '["RUN touch /onbuild3"]' ".Config.OnBuild"
+  expect_output '["RUN touch /onbuild3"]'
   cid=$(buildah from ${target})
   root=$(buildah mount ${cid})
   run ls ${root}/onbuild1 ${root}/onbuild2 ${root}/onbuild3
@@ -809,7 +809,7 @@ load helpers
   target=onbuild-image3
   buildah commit --signature-policy ${TESTSDIR}/policy.json --format docker ${cid} ${target}
   run_buildah --debug=false inspect --format '{{printf "%q" .Docker.Config.OnBuild}}' ${target}
-  is "$output" '["RUN touch /onbuild4"]' ".Config.OnBuild"
+  expect_output '["RUN touch /onbuild4"]'
   buildah rm ${cid}
   buildah rmi --all
 }
@@ -817,39 +817,37 @@ load helpers
 @test "bud-onbuild-layers" {
   target=onbuild
   buildah bud --format docker --signature-policy ${TESTSDIR}/policy.json --layers -t ${target} -f Dockerfile2 ${TESTSDIR}/bud/onbuild
-  run buildah --debug=false inspect --format '{{printf "%q" .Docker.Config.OnBuild}}' ${target}
-  echo "$output"
-  [ "$status" -eq 0 ]
-  [ "$output" = '["RUN touch /onbuild1" "RUN touch /onbuild2"]' ]
+  run_buildah --debug=false inspect --format '{{printf "%q" .Docker.Config.OnBuild}}' ${target}
+  expect_output '["RUN touch /onbuild1" "RUN touch /onbuild2"]'
 }
 
 @test "bud-logfile" {
   rm -f ${TESTDIR}/logfile
   run_buildah bud --logfile ${TESTDIR}/logfile --signature-policy ${TESTSDIR}/policy.json ${TESTSDIR}/bud/preserve-volumes
-  is "$output" "" "buildah bud output"
+  expect_output ""
   test -s ${TESTDIR}/logfile
 }
 
 @test "bud with ARGS" {
   target=alpine-image
   run_buildah --debug=false bud -q --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile.args ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*arg_value" "buildah bud output"
+  expect_output --substring "arg_value"
 }
 
 @test "bud with unused ARGS" {
   target=alpine-image
   run_buildah --debug=false bud -q --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile.multi-args --build-arg USED_ARG=USED_VALUE ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*USED_VALUE" "buildah bud output"
+  expect_output --substring "USED_VALUE"
   [[ ! "$output" =~ "one or more build args were not consumed: [UNUSED_ARG]" ]]
   run_buildah --debug=false bud -q --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile.multi-args --build-arg USED_ARG=USED_VALUE --build-arg UNUSED_ARG=whaaaat ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*USED_VALUE" "buildah bud output"
-  is "$output" ".*one or more build args were not consumed: \[UNUSED_ARG\]" "buildah bud output"
+  expect_output --substring "USED_VALUE"
+  expect_output --substring "one or more build args were not consumed: \[UNUSED_ARG\]"
 }
 
 @test "bud with multi-value ARGS" {
   target=alpine-image
   run_buildah --debug=false bud -q --signature-policy ${TESTSDIR}/policy.json -t ${target} -f Dockerfile.multi-args --build-arg USED_ARG=plugin1,plugin2,plugin3 ${TESTSDIR}/bud/run-scenarios
-  is "$output" ".*plugin1,plugin2,plugin3" "buildah bud output"
+  expect_output --substring "plugin1,plugin2,plugin3"
   [[ ! "$output" =~ "one or more build args were not consumed: [UNUSED_ARG]" ]]
 }
 
@@ -864,7 +862,7 @@ load helpers
   buildah rm ${cid}
   buildah rmi $(buildah --debug=false images -q)
   run_buildah --debug=false images -q
-  is "$output" "" "buildah images -q"
+  expect_output ""
 }
 
 @test "bud with preprocessor" {
@@ -880,89 +878,89 @@ load helpers
 @test "bud-with-rejected-name" {
   target=ThisNameShouldBeRejected
   run_buildah 1 --debug=false bud -q --signature-policy ${TESTSDIR}/policy.json -t ${target} ${TESTSDIR}/bud/from-scratch
-  is "$output" ".*must be lower" "buildah bud output"
+  expect_output --substring "must be lower"
 }
 
 @test "bud with chown copy" {
   imgName=alpine-image
   ctrName=alpine-chown
   run_buildah --debug=false bud --signature-policy ${TESTSDIR}/policy.json -t ${imgName} ${TESTSDIR}/bud/copy-chown
-  is "$output" ".*user:2367 group:3267" "buildah bud output"
+  expect_output --substring "user:2367 group:3267"
   run_buildah --debug=false from --name ${ctrName} ${imgName}
   run_buildah --debug=false run alpine-chown -- stat -c '%u' /tmp/copychown.txt
   # Validate that output starts with "2367"
-  is "$output" "2367.*" "output from stat"
+  expect_output --substring "2367"
 
   run_buildah --debug=false run alpine-chown -- stat -c '%g' /tmp/copychown.txt
   # Validate that output starts with "3267"
-  is "$output" "3267.*" "output from stat"
+  expect_output --substring "3267"
 }
 
 @test "bud with chown add" {
   imgName=alpine-image
   ctrName=alpine-chown
   run_buildah --debug=false bud --signature-policy ${TESTSDIR}/policy.json -t ${imgName} ${TESTSDIR}/bud/add-chown
-  is "$output" ".*user:2367 group:3267" "buildah bud output"
+  expect_output --substring "user:2367 group:3267"
   run_buildah --debug=false from --name ${ctrName} ${imgName}
   run_buildah --debug=false run alpine-chown -- stat -c '%u' /tmp/addchown.txt
   # Validate that output starts with "2367"
-  is "$output" "2367.*" "output from stat"
+  expect_output --substring "2367"
 
   run_buildah --debug=false run alpine-chown -- stat -c '%g' /tmp/addchown.txt
   # Validate that output starts with "3267"
-  is "$output" "3267.*" "output from stat"
+  expect_output --substring "3267"
 }
 
 @test "bud with ADD file construct" {
   buildah --debug=false bud --signature-policy ${TESTSDIR}/policy.json -t test1 ${TESTSDIR}/bud/add-file
   run_buildah --debug=false images -a
-  is "$output" ".*test1" "buildah images -a"
+  expect_output --substring "test1"
 
   ctr=$(buildah --debug=false from --signature-policy ${TESTSDIR}/policy.json test1)
   run_buildah --debug=false containers -a
-  is "$output" ".*test1" "buildah containers -a"
+  expect_output --substring "test1"
 
   run_buildah --debug=false run $ctr ls /var/file2
-  is "$output" ".*/var/file2" "buildah run ls"
+  expect_output --substring "/var/file2"
 }
 
 @test "bud with FROM AS construct" {
   buildah bud --signature-policy ${TESTSDIR}/policy.json -t test1 ${TESTSDIR}/bud/from-as
   run_buildah --debug=false images -a
-  is "$output"  ".*test1" "buildah images -a"
+  expect_output --substring "test1"
 
   ctr=$(buildah --debug=false from --signature-policy ${TESTSDIR}/policy.json test1)
   run_buildah --debug=false containers -a
-  is "$output" ".*test1" "buildah containers -a"
+  expect_output --substring "test1"
 
   run_buildah inspect --format "{{.Docker.ContainerConfig.Env}}" --type image test1
-  is "$output" ".*LOCAL=/1" ".ContainerConfig.Env"
+  expect_output --substring "LOCAL=/1"
 }
 
 @test "bud with FROM AS construct with layers" {
   buildah bud --layers --signature-policy ${TESTSDIR}/policy.json -t test1 ${TESTSDIR}/bud/from-as
   run_buildah --debug=false images -a
-  is "$output" ".*test1" "buildah images -a"
+  expect_output --substring "test1"
 
   ctr=$(buildah --debug=false from --signature-policy ${TESTSDIR}/policy.json test1)
   run_buildah --debug=false containers -a
-  is "$output" ".*test1" "buildah containers -a"
+  expect_output --substring "test1"
 
   run_buildah inspect --format "{{.Docker.ContainerConfig.Env}}" --type image test1
-  is "$output" ".*LOCAL=/1" ".ContainerConfig.Env"
+  expect_output --substring "LOCAL=/1"
 }
 
 @test "bud with FROM AS skip FROM construct" {
   run_buildah --debug=false bud --signature-policy ${TESTSDIR}/policy.json -t test1 -f ${TESTSDIR}/bud/from-as/Dockerfile.skip ${TESTSDIR}/bud/from-as
-  is "$output" ".*LOCAL=/1" "buildah bud output"
-  is "$output" ".*LOCAL2=/2" "buildah bud output"
+  expect_output --substring "LOCAL=/1"
+  expect_output --substring "LOCAL2=/2"
 
   run_buildah --debug=false images -a
-  is "$output" ".*test1" "buildah images -a"
+  expect_output --substring "test1"
 
   ctr=$(buildah --debug=false from --signature-policy ${TESTSDIR}/policy.json test1)
   run_buildah --debug=false containers -a
-  is "$output" ".*test1" "buildah containers -a"
+  expect_output --substring "test1"
 
   mnt=$(buildah mount $ctr)
   run test -e $mnt/1
@@ -971,25 +969,25 @@ load helpers
   [ "${status}" -ne 0 ]
 
   run_buildah --debug=false inspect --format "{{.Docker.ContainerConfig.Env}}" --type image test1
-  is "$output" "[PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin LOCAL=/1]" ".ContainerConfig.Env"
+  expect_output "[PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin LOCAL=/1]"
 }
 
 @test "bud with symlink Dockerfile not specified in file" {
   target=alpine-image
   run_buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/symlink ${TESTSDIR}/bud/symlink
-  is "$output" ".*FROM alpine" "buildah bud output"
+  expect_output --substring "FROM alpine"
 }
 
 @test "bud with dir for file but no Dockerfile in dir" {
   target=alpine-image
   run_buildah 1 bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/empty-dir ${TESTSDIR}/bud/empty-dir
-  is "$output" ".*no such file or directory" "buildah bud output"
+  expect_output --substring "no such file or directory"
 }
 
 @test "bud with bad dir Dockerfile" {
   target=alpine-image
   run_buildah 1 bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/baddirname ${TESTSDIR}/baddirname
-  is "$output" ".*no such file or directory" "buildah bud output"
+  expect_output --substring "no such file or directory"
 }
 
 @test "bud with ARG before FROM default value" {
@@ -1010,7 +1008,7 @@ load helpers
   threeseconds=$(( 3 * $second ))
   fiveminutes=$(( 5 * 60 * $second ))
   tenminutes=$(( 10 * 60 * $second ))
-  is "$output" '["CMD-SHELL" "curl -f http://localhost/ || exit 1"]'" $tenminutes $fiveminutes $threeseconds 4" "Healthcheck config"
+  expect_output '["CMD-SHELL" "curl -f http://localhost/ || exit 1"]'" $tenminutes $fiveminutes $threeseconds 4" "Healthcheck config"
 }
 
 @test "bud with unused build arg" {
@@ -1045,8 +1043,8 @@ load helpers
 @test "bud-target" {
   target=target
   run_buildah bud --debug=false --signature-policy ${TESTSDIR}/policy.json -t ${target} --target mytarget ${TESTSDIR}/bud/target
-  is "$output" ".*STEP 1: FROM ubuntu:latest" "buildah bud output"
-  is "$output" ".*STEP 3: FROM alpine:latest AS mytarget" "buildah bud output"
+  expect_output --substring "STEP 1: FROM ubuntu:latest"
+  expect_output --substring "STEP 3: FROM alpine:latest AS mytarget"
   cid=$(buildah from ${target})
   root=$(buildah mount ${cid})
   run ls ${root}/2
diff --git a/tests/commit.bats b/tests/commit.bats
index 7c827404659..270fbf493a3 100644
--- a/tests/commit.bats
+++ b/tests/commit.bats
@@ -38,7 +38,7 @@ load helpers
 @test "commit quiet test" {
   cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false commit --iidfile /dev/null --signature-policy ${TESTSDIR}/policy.json -q $cid alpine-image
-  is "$output" "" "no output from commit"
+  expect_output ""
   buildah rm $cid
   buildah rmi -a
 }
@@ -47,7 +47,7 @@ load helpers
   cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   buildah commit --signature-policy ${TESTSDIR}/policy.json --rm $cid alpine-image
   run_buildah 1 --debug=false rm $cid
-  is "$output" ".*error removing container \"alpine-working-container\": error reading build container: container not known" "buildah rm"
+  expect_output --substring "error removing container \"alpine-working-container\": error reading build container: container not known"
   buildah rmi -a
 }
 
@@ -63,7 +63,7 @@ load helpers
 @test "commit-rejected-name" {
   cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah 1 --debug=false commit --signature-policy ${TESTSDIR}/policy.json $cid ThisNameShouldBeRejected
-  is "$output" ".*must be lower" "buildah commit output"
+  expect_output --substring "must be lower"
 }
 
 @test "commit-no-empty-created-by" {
diff --git a/tests/config.bats b/tests/config.bats
index d41f17b97c0..efdf536d859 100644
--- a/tests/config.bats
+++ b/tests/config.bats
@@ -20,10 +20,11 @@ function check_matrix() {
   local setting=$1
   local expect=$2
 
+  # matrix test: all permutations of .Docker.* and .OCIv1.* in all image types
   for image in docker oci; do
       for which in Docker OCIv1; do
         run_buildah --debug=false inspect --type=image --format "{{.$which.$setting}}" scratch-image-$image
-        is "$output" "$expect" "scratch-image-$image > .$which.$setting"
+        expect_output "$expect"
     done
   done
 }
@@ -144,16 +145,16 @@ function check_matrix() {
 
   buildah --debug=false inspect --format '{{.ImageCreatedBy}}' $cid | grep COINCIDENCE
 
-  check_matrix 'Config.User'         'likes:things'
-  check_matrix 'Config.ExposedPorts' 'map[12345:{}]'
-  check_matrix 'Config.Env'          '[VARIABLE=VALUE1,VALUE2]'
-  check_matrix 'Config.Entrypoint'   '[/bin/sh -c /ENTRYPOINT]'
   check_matrix 'Config.Cmd'          '[COMMAND-OR-ARGS]'
+  check_matrix 'Config.Entrypoint'   '[/bin/sh -c /ENTRYPOINT]'
+  check_matrix 'Config.Env'          '[VARIABLE=VALUE1,VALUE2]'
+  check_matrix 'Config.ExposedPorts' 'map[12345:{}]'
+  check_matrix 'Config.Labels.exec'  'podman run -it --mount=type=bind,bind-propagation=Z,source=foo,destination=bar /script buz'
+  check_matrix 'Config.Labels.LABEL' 'VALUE'
+  check_matrix 'Config.StopSignal'   'SIGINT'
+  check_matrix 'Config.User'         'likes:things'
   check_matrix 'Config.Volumes'      'map[/VOLUME:{}]'
   check_matrix 'Config.WorkingDir'   '/tmp'
-  check_matrix 'Config.Labels'       '.*LABEL:VALUE'
-  check_matrix 'Config.Labels'       '.*exec:podman run -it --mount=type=bind,bind-propagation=Z,source=foo,destination=bar /script buz'
-  check_matrix 'Config.StopSignal'   'SIGINT'
 
   buildah --debug=false inspect --type=image --format '{{(index .Docker.History 0).Comment}}' scratch-image-docker | grep PROBABLY-EMPTY
   buildah --debug=false inspect --type=image --format '{{(index .OCIv1.History 0).Comment}}' scratch-image-docker | grep PROBABLY-EMPTY
@@ -182,10 +183,10 @@ function check_matrix() {
   buildah commit --format oci --signature-policy ${TESTSDIR}/policy.json $cid env-image-oci
 
   run_buildah --debug=false inspect --type=image --format '{{.Docker.Config.Env}}' env-image-docker
-  is "$output" ".*combined=bar/bar1" ".Docker.Config.Env"
+  expect_output --substring "combined=bar/bar1"
 
   run_buildah --debug=false inspect --type=image --format '{{.OCIv1.Config.Env}}' env-image-docker
-  is "$output" ".*combined=bar/bar1" ".OCIv1.Config.Env"
+  expect_output --substring "combined=bar/bar1"
 
   buildah rm $cid
   buildah rmi env-image-docker env-image-oci
@@ -196,13 +197,13 @@ function check_matrix() {
   bndoutput=$(buildah --debug=false run $cid grep CapBnd /proc/self/status)
   buildah config --user 1000 $cid
   run_buildah --debug=false run $cid id -u
-  is "$output" "1000" "id -u in container"
+  expect_output "1000"
 
   run_buildah --debug=false run $cid sh -c "grep CapEff /proc/self/status | cut -f2"
-  is "$output" "0000000000000000" "CapEff in /proc/self/status"
+  expect_output "0000000000000000"
 
   run_buildah --debug=false run $cid grep CapBnd /proc/self/status
-  is "$output" "$bndoutput" "CapBnd in /proc/self/status"
+  expect_output "$bndoutput"
 
   buildah rm $cid
 }
diff --git a/tests/from.bats b/tests/from.bats
index 5f3ca47f9f4..a5301781bad 100644
--- a/tests/from.bats
+++ b/tests/from.bats
@@ -218,7 +218,7 @@ load helpers
   fi
   cid=$(buildah from --cpu-period=5000 --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false run $cid cat /sys/fs/cgroup/cpu/cpu.cfs_period_us
-  is "$output" "5000" "cpu.cfs_period_us"
+  expect_output "5000"
   buildah rm $cid
 }
 
@@ -231,7 +231,7 @@ load helpers
   fi
   cid=$(buildah from --cpu-quota=5000 --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false run $cid cat /sys/fs/cgroup/cpu/cpu.cfs_quota_us
-  is "$output" "5000" "cpu.cfs_quota_us"
+  expect_output "5000"
   buildah rm $cid
 }
 
@@ -244,7 +244,7 @@ load helpers
   fi
   cid=$(buildah from --cpu-shares=2 --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false run $cid cat /sys/fs/cgroup/cpu/cpu.shares
-  is "$output" "1024" "cpu.shares"
+  expect_output "1024"
   buildah rm $cid
 }
 
@@ -257,7 +257,7 @@ load helpers
   fi
   cid=$(buildah from --cpuset-cpus=0 --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false run $cid cat /sys/fs/cgroup/cpuset/cpuset.cpus
-  is "$output" "0" "cpuset.cpus"
+  expect_output "0"
   buildah rm $cid
 }
 
@@ -270,7 +270,7 @@ load helpers
   fi
   cid=$(buildah from --cpuset-mems=0 --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false run $cid cat /sys/fs/cgroup/cpuset/cpuset.mems
-  is "$output" "0" "cpuset.mems"
+  expect_output "0"
   buildah rm $cid
 }
 
@@ -283,7 +283,7 @@ load helpers
   fi
   cid=$(buildah from --memory=40m --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false run $cid cat /sys/fs/cgroup/memory/memory.limit_in_bytes
-  is "$output" "41943040" "memory.limit_in_bytes"
+  expect_output "41943040"
   buildah rm $cid
 }
 
@@ -293,7 +293,7 @@ load helpers
   fi
   cid=$(buildah from --volume=${TESTDIR}:/myvol --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false run $cid -- cat /proc/mounts
-  is "$output" ".* /myvol " "/proc/mounts"
+  expect_output --substring " /myvol "
   buildah rm $cid
 }
 
@@ -306,7 +306,7 @@ load helpers
   fi
   cid=$(buildah from --volume=${TESTDIR}:/myvol:ro --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false run $cid -- cat /proc/mounts
-  is "$output" ".* /myvol " "/proc/mounts"
+  expect_output --substring " /myvol "
   buildah rm $cid
 }
 
@@ -319,7 +319,7 @@ load helpers
   fi
   cid=$(buildah from --shm-size=80m --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah --debug=false run $cid -- df -h
-  is "$output" ".* 80.0M " "df -h"
+  expect_output --substring " 80.0M "
   buildah rm $cid
 }
 
@@ -329,7 +329,7 @@ load helpers
   fi
   cid=$(buildah from --add-host=localhost:127.0.0.1 --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah run $cid -- cat /etc/hosts
-  is "$output" ".*127.0.0.1 +localhost" "/etc/hosts"
+  expect_output --substring "127.0.0.1 +localhost"
   buildah rm $cid
 }
 
diff --git a/tests/helpers.bash b/tests/helpers.bash
index 9d503b25a2a..30cce390b7e 100644
--- a/tests/helpers.bash
+++ b/tests/helpers.bash
@@ -128,22 +128,49 @@ function die() {
     false
 }
 
-########
-#  is  #  Compare actual vs expected string; fail w/diagnostic if mismatch
-########
+###################
+#  expect_output  #  Compare actual vs expected string; fail if mismatch
+###################
 #
-# Compares given string against expectations, using '=~' to allow patterns.
+# Compares $output against the given string argument. Optional second
+# argument is descriptive text to show as the error message (default:
+# the command most recently run by 'run_buildah'). This text can be
+# useful to isolate a failure when there are multiple identical
+# run_buildah invocations, and the difference is solely in the
+# config or setup; see, e.g., run.bats:run-cmd().
+#
+# By default we run an exact string comparison; use --substring to
+# look for the given string anywhere in $output.
+#
+# By default we look in "$output", which is set in run_buildah().
+# To override, use --from="some-other-string" (e.g. "${lines[0]}")
 #
 # Examples:
 #
-#   is "$actual" "$expected" "descriptive test name"
-#   is "apple" "orange"  "name of a test that will fail in most universes"
-#   is "apple" "[a-z]\+" "this time it should pass"
+#   expect_output "this is exactly what we expect"
+#   expect_output "foo=bar"  "description of this particular test"
+#   expect_output --from="${lines[0]}"  "expected first line"
 #
-function is() {
-    local actual="$1"
-    local expect="$2"
-    local testname="${3:-FIXME}"
+function expect_output() {
+    # By default we examine $output, the result of run_buildah
+    local actual="$output"
+    local check_substring=
+
+    # option processing: recognize --from="...", --substring
+    local opt
+    for opt; do
+        local value=$(expr "$opt" : '[^=]*=\(.*\)')
+        case "$opt" in
+            --from=*)       actual="$value";   shift;;
+            --substring)    check_substring=1; shift;;
+            --)             shift; break;;
+            -*)             die "Invalid option '$opt'" ;;
+            *)              break;;
+        esac
+    done
+
+    local expect="$1"
+    local testname="${2:-${MOST_RECENT_BUILDAH_COMMAND:-[no test name given]}}"
 
     if [ -z "$expect" ]; then
         if [ -z "$actual" ]; then
@@ -152,8 +179,10 @@ function is() {
         expect='[no output]'
     elif [ "$actual" = "$expect" ]; then
 	return
-    elif [[ "$actual" =~ ^$expect ]]; then
-        return
+    elif [ -n "$check_substring" ]; then
+        if [[ "$actual" =~ $expect ]]; then
+            return
+        fi
     fi
 
     # This is a multi-line message, which may in turn contain multi-line
diff --git a/tests/images.bats b/tests/images.bats
index 62224b7291b..08553ba1ec0 100644
--- a/tests/images.bats
+++ b/tests/images.bats
@@ -81,7 +81,7 @@ load helpers
   cid2=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json busybox)
   run_buildah --debug=false images -q --no-trunc
   expect_line_count 2
-  is "${lines[0]}" ".*sha256" "images --no-trunc"
+  expect_output --substring --from="${lines[0]}" "sha256"
   buildah rm -a
   buildah rmi -a -f
 }
@@ -135,7 +135,7 @@ load helpers
 
 @test "specify a nonexistent image" {
   run_buildah 1 --debug=false images alpine
-  is "${lines[0]}" "No such image alpine" "buildah images"
+  expect_output --from="${lines[0]}" "No such image alpine"
   expect_line_count 1
 }
 
@@ -147,11 +147,11 @@ load helpers
   expect_line_count 3
 
   run_buildah --debug=false images --filter dangling=true
-  is "$output" ".* <none> " "images ... dangling=true"
+  expect_output --substring " <none> "
   expect_line_count 2
 
   run_buildah --debug=false images --filter dangling=false
-  is "$output" ".* latest " "images ... dangling=false"
+  expect_output --substring " latest "
   expect_line_count 2
 
   buildah rm -a
diff --git a/tests/mount.bats b/tests/mount.bats
index 36b68812c40..2df1b53578c 100644
--- a/tests/mount.bats
+++ b/tests/mount.bats
@@ -50,9 +50,9 @@ load helpers
   cid3=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   buildah mount "$cid3"
   run_buildah --debug=false mount
-  is "${lines[0]}" ".*/tmp" "mount line 1 of 3"
-  is "${lines[1]}" ".*/tmp" "mount line 2 of 3"
-  is "${lines[2]}" ".*/tmp" "mount line 3 of 3"
+  expect_output --from="${lines[0]}" --substring "/tmp" "mount line 1 of 3"
+  expect_output --from="${lines[1]}" --substring "/tmp" "mount line 2 of 3"
+  expect_output --from="${lines[2]}" --substring "/tmp" "mount line 3 of 3"
   expect_line_count 3
 
   buildah rm --all
diff --git a/tests/namespaces.bats b/tests/namespaces.bats
index c02afeac77d..5549f7c99fa 100644
--- a/tests/namespaces.bats
+++ b/tests/namespaces.bats
@@ -188,21 +188,21 @@ load helpers
     run_buildah copy --chown 1:1 "$ctr" ${TESTDIR}/somefile /
     buildah run $RUNOPTS "$ctr" stat -c '%u:%g' /somefile
     run_buildah --debug=false run $RUNOPTS "$ctr" stat -c '%u:%g' /somefile
-    is "$output" "1:1" "stat /somefile"
+    expect_output "1:1"
 
     # Check that if we copy a directory into the container, its contents get the right permissions.
     run_buildah copy "$ctr" ${TESTDIR}/somedir /somedir
     buildah run $RUNOPTS "$ctr" stat -c '%u:%g' /somedir
     run_buildah --debug=false run $RUNOPTS "$ctr" stat -c '%u:%g' /somedir
-    is "$output" "0:0" "stat /somedir"
+    expect_output "0:0"
     run_buildah --debug=false mount "$ctr"
     mnt="$output"
     run stat -c '%u:%g %a' "$mnt"/somedir/someotherfile
     [ $status -eq 0 ]
-    is "$output" "$rootuid:$rootgid 4700" "stat from host"
+    expect_output "$rootuid:$rootgid 4700"
     buildah run $RUNOPTS "$ctr" stat -c '%u:%g %a' /somedir/someotherfile
     run_buildah --debug=false run $RUNOPTS "$ctr" stat -c '%u:%g %a' /somedir/someotherfile
-    is "$output" "0:0 4700" "stat inside container"
+    expect_output "0:0 4700"
   done
 }
 
diff --git a/tests/pull.bats b/tests/pull.bats
index e60eeb057de..81988255eff 100644
--- a/tests/pull.bats
+++ b/tests/pull.bats
@@ -15,7 +15,7 @@ load helpers
 
 @test "pull-blocked" {
   run_buildah 1 --registries-conf ${TESTSDIR}/registries.conf.block pull --signature-policy ${TESTSDIR}/policy.json docker.io/alpine
-  is "$output" ".*is blocked by configuration" "sdfsdfsdf FIXME"
+  expect_output --substring "is blocked by configuration"
 
   run_buildah --registries-conf ${TESTSDIR}/registries.conf       pull --signature-policy ${TESTSDIR}/policy.json docker.io/alpine
 }
@@ -24,17 +24,17 @@ load helpers
   run_buildah pull --registries-conf ${TESTSDIR}/registries.conf --signature-policy ${TESTSDIR}/policy.json busybox:glibc
   run_buildah pull --registries-conf ${TESTSDIR}/registries.conf --signature-policy ${TESTSDIR}/policy.json busybox
   run_buildah images --format "{{.Name}}:{{.Tag}}"
-  is "$output" ".*busybox:glibc"  "'buildah images' includes busybox:glibc"
-  is "$output" ".*busybox:latest" "'buildah images' includes busybox:latest"
+  expect_output --substring "busybox:glibc"
+  expect_output --substring "busybox:latest"
 
   run_buildah pull --registries-conf ${TESTSDIR}/registries.conf --signature-policy ${TESTSDIR}/policy.json quay.io/libpod/alpine_nginx:latest
   run_buildah images --format "{{.Name}}:{{.Tag}}"
-  is "$output" ".*alpine_nginx:latest" "pulled alpine_nginx:latest"
+  expect_output --substring "alpine_nginx:latest"
 
   run_buildah rmi quay.io/libpod/alpine_nginx:latest
   run_buildah pull --registries-conf ${TESTSDIR}/registries.conf --signature-policy ${TESTSDIR}/policy.json quay.io/libpod/alpine_nginx
   run_buildah images --format "{{.Name}}:{{.Tag}}"
-  is "$output" ".*alpine_nginx:latest" "rmi'ed then re-pulled alpine_nginx"
+  expect_output --substring "alpine_nginx:latest"
 
   run_buildah pull --registries-conf ${TESTSDIR}/registries.conf --signature-policy ${TESTSDIR}/policy.json alpine@sha256:1072e499f3f655a032e88542330cf75b02e7bdf673278f701d7ba61629ee3ebe
   run_buildah 1 pull --registries-conf ${TESTSDIR}/registries.conf --signature-policy ${TESTSDIR}/policy.json fakeimage/fortest
@@ -48,7 +48,7 @@ load helpers
   run_buildah rmi alpine
   run_buildah pull --signature-policy ${TESTSDIR}/policy.json docker-archive:${TESTDIR}/alp.tar
   run_buildah images --format "{{.Name}}:{{.Tag}}"
-  is "$output" ".*alpine" "buildah images"
+  expect_output --substring "alpine"
   run_buildah 1 pull --all-tags --signature-policy ${TESTSDIR}/policy.json docker-archive:${TESTDIR}/alp.tar
   run rm -rf ${TESTDIR}/alp.tar
   echo "$output"
@@ -61,7 +61,7 @@ load helpers
   run_buildah rmi alpine
   run_buildah pull --signature-policy ${TESTSDIR}/policy.json oci-archive:${TESTDIR}/alp.tar
   run_buildah images --format "{{.Name}}:{{.Tag}}"
-  is "$output" ".*alpine" "buildah images"
+  expect_output --substring "alpine"
   run_buildah 1 pull --all-tags --signature-policy ${TESTSDIR}/policy.json oci-archive:${TESTDIR}/alp.tar
   run rm -rf ${TESTDIR}/alp.tar
   echo "$output"
@@ -75,7 +75,7 @@ load helpers
   run_buildah rmi alpine
   run_buildah pull --signature-policy ${TESTSDIR}/policy.json dir:${TESTDIR}/buildahtest
   run_buildah images --format "{{.Name}}:{{.Tag}}"
-  is "$output" ".*buildahtest" "buildah images"
+  expect_output --substring "buildahtest"
   run_buildah 1 pull --all-tags --signature-policy ${TESTSDIR}/policy.json dir:${TESTDIR}/buildahtest
   run rm -rf ${TESTDIR}/buildahtest
   echo "$output"
@@ -97,7 +97,7 @@ load helpers
   [ "$status" -eq 0 ]
   run_buildah pull --signature-policy ${TESTSDIR}/policy.json docker-daemon:docker.io/library/alpine:latest
   run_buildah images --format "{{.Name}}:{{.Tag}}"
-  is "$output" ".*alpine:latest" "buildah images"
+  expect_output --substring "alpine:latest"
   run_buildah rmi alpine
   run_buildah 1 pull --all-tags --signature-policy ${TESTSDIR}/policy.json docker-daemon:docker.io/library/alpine:latest
   run docker rmi -f alpine:latest
@@ -121,13 +121,13 @@ load helpers
   run_buildah rmi alpine
   run_buildah pull --signature-policy ${TESTSDIR}/policy.json ostree:alpine@${TESTDIR}/ostree-repo
   run_buildah images --format "{{.Name}}:{{.Tag}}"
-  is "$output" ".*ostree-repo:latest" "buildah images"
+  expect_output --substring "ostree-repo:latest"
 }
 
 
 @test "pull-all-tags" {
   run_buildah pull --signature-policy ${TESTSDIR}/policy.json --all-tags alpine
-  is "$output" ".*alpine:latest" "buildah pull"
+  expect_output --substring "alpine:latest"
 
   run_buildah images -q
   [ $(wc -l <<< "$output") -ge 3 ]
@@ -139,7 +139,7 @@ load helpers
   run_buildah rmi alpine
   run_buildah pull --signature-policy ${TESTSDIR}/policy.json oci:${TESTDIR}/alpine
   run_buildah images --format "{{.Name}}:{{.Tag}}"
-  is "$output" ".*alpine" "buildah images"
+  expect_output --substring "alpine"
   run_buildah 1 pull --all-tags --signature-policy ${TESTSDIR}/policy.json oci:${TESTDIR}/alpine
   run rm -rf ${TESTDIR}/alpine
   echo "$output"
diff --git a/tests/push.bats b/tests/push.bats
index ebdbad1d6a0..0ea941cc783 100644
--- a/tests/push.bats
+++ b/tests/push.bats
@@ -65,6 +65,6 @@ load helpers
 @test "push without destination" {
   buildah pull --signature-policy ${TESTSDIR}/policy.json busybox
   run_buildah 1 push --signature-policy ${TESTSDIR}/policy.json busybox
-  is "$output" ".*docker://busybox" "output of buildah push"
+  expect_output --substring "docker://busybox"
   buildah rmi busybox
 }
diff --git a/tests/registries.bats b/tests/registries.bats
index 55cd03188b6..b1d00e219a9 100644
--- a/tests/registries.bats
+++ b/tests/registries.bats
@@ -27,7 +27,7 @@ load helpers
       run_buildah --debug=false inspect -f "{{.FromImageID}}" $cid
       expect_line_count 1
       if [ "$lastid" != "" ] ; then
-        is "$output" "$lastid" ".FromImageId"
+        expect_output "$lastid"
       fi
       lastid="$output"
     done
diff --git a/tests/rename.bats b/tests/rename.bats
index 016ed0598e2..9ba5e28783a 100644
--- a/tests/rename.bats
+++ b/tests/rename.bats
@@ -9,10 +9,10 @@ load helpers
   buildah rename ${cid} ${new_name}
 
   run_buildah containers --format "{{.ContainerName}}"
-  is "$output" ".*test-container" "buildah containers"
+  expect_output --substring "test-container"
 
   run_buildah --debug=false containers --quiet -f name=${old_name}
-  is "$output" "" "old_name no longer in buildah containers"
+  expect_output ""
 
   buildah rm ${new_name}
   [ "$status" -eq 0 ]
@@ -21,7 +21,7 @@ load helpers
 @test "rename same name as current name" {
   cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah 1 --debug=false rename ${cid} ${cid}
-  is "$output" 'renaming a container with the same name as its current name' "output of buildah rename"
+  expect_output 'renaming a container with the same name as its current name'
 
   buildah rm $cid
   buildah rmi -f alpine
@@ -31,7 +31,7 @@ load helpers
   cid1=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   cid2=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json busybox)
   run_buildah 1 --debug=false rename ${cid1} ${cid2}
-  is "$output" ".* already in use by " "output of buildah rename"
+  expect_output --substring " already in use by "
 
   buildah rm $cid1 $cid2
   buildah rmi -f alpine busybox
diff --git a/tests/rm.bats b/tests/rm.bats
index 1b2f7187cb4..3d61a1d9593 100644
--- a/tests/rm.bats
+++ b/tests/rm.bats
@@ -12,9 +12,9 @@ load helpers
 
 @test "remove multiple containers errors" {
   run_buildah 1 --debug=false rm mycontainer1 mycontainer2 mycontainer3
-  is "${lines[0]}" "error removing container \"mycontainer1\": error reading build container: container not known" "output line 1"
-  is "${lines[1]}" "error removing container \"mycontainer2\": error reading build container: container not known" "output line 2"
-  is "${lines[2]}" "error removing container \"mycontainer3\": error reading build container: container not known" "output line 3"
+  expect_output --from="${lines[0]}" "error removing container \"mycontainer1\": error reading build container: container not known" "output line 1"
+  expect_output --from="${lines[1]}" "error removing container \"mycontainer2\": error reading build container: container not known" "output line 2"
+  expect_output --from="${lines[2]}" "error removing container \"mycontainer3\": error reading build container: container not known" "output line 3"
   expect_line_count 3
 }
 
@@ -42,7 +42,7 @@ load helpers
 @test "use conflicting commands to remove containers" {
   cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   run_buildah 1 --debug=false rm -a "$cid"
-  is "$output" ".*when using the --all switch, you may not pass any containers names or IDs" "output from buildah rm -a cid"
+  expect_output --substring "when using the --all switch, you may not pass any containers names or IDs"
   run_buildah rm "$cid"
   run_buildah rmi alpine
 }
diff --git a/tests/rmi.bats b/tests/rmi.bats
index 99580dfec99..f713ed33705 100644
--- a/tests/rmi.bats
+++ b/tests/rmi.bats
@@ -18,7 +18,7 @@ load helpers
   buildah rm "$cid"
   buildah rmi alpine
   run_buildah --debug=false images -q
-  is "$output" "" "images -q"
+  expect_output ""
 }
 
 @test "remove multiple images" {
@@ -30,14 +30,14 @@ load helpers
 
   buildah rmi -f alpine busybox
   run_buildah --debug=false images -q
-  is "$output" "" "images -q"
+  expect_output ""
 }
 
 @test "remove multiple non-existent images errors" {
   run_buildah 1 --debug=false rmi image1 image2 image3
-  is "${lines[0]}" "could not get image \"image1\": identifier is not an image" "output line 1"
-  is "${lines[1]}" "could not get image \"image2\": identifier is not an image" "output line 2"
-  is "${lines[2]}" "could not get image \"image3\": identifier is not an image" "output line 3"
+  expect_output --from="${lines[0]}" "could not get image \"image1\": identifier is not an image" "output line 1"
+  expect_output --from="${lines[1]}" "could not get image \"image2\": identifier is not an image" "output line 2"
+  expect_output --from="${lines[2]}" "could not get image \"image3\": identifier is not an image" "output line 3"
   [ $(wc -l <<< "$output") -gt 2 ]
 }
 
@@ -47,7 +47,7 @@ load helpers
   cid3=$(buildah from --signature-policy ${TESTSDIR}/policy.json busybox)
   buildah rmi -a -f
   run_buildah --debug=false images -q
-  is "$output" "" "images -q"
+  expect_output ""
 
   cid1=$(buildah from --signature-policy ${TESTSDIR}/policy.json scratch)
   cid2=$(buildah from --signature-policy ${TESTSDIR}/policy.json alpine)
@@ -58,7 +58,7 @@ load helpers
 
   buildah rmi --all --force
   run_buildah --debug=false images -q
-  is "$output" "" "images -q"
+  expect_output ""
 }
 
 @test "use prune to remove dangling images" {
@@ -93,24 +93,24 @@ load helpers
 
   buildah rmi --all --force
   run_buildah --debug=false images -q
-  is "$output" "" "images -q"
+  expect_output ""
 }
 
 @test "use conflicting commands to remove images" {
   cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   buildah rm "$cid"
   run_buildah 1 --debug=false rmi -a alpine
-  is "$output" ".*when using the --all switch, you may not pass any images names or IDs" "rmi -a with name"
+  expect_output --substring "when using the --all switch, you may not pass any images names or IDs"
 
   cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   buildah rm "$cid"
   run_buildah 1 --debug=false rmi -p alpine
-  is "$output" ".*when using the --prune switch, you may not pass any images names or IDs" "rmi -p with name"
+  expect_output --substring "when using the --prune switch, you may not pass any images names or IDs"
 
   cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
   buildah rm "$cid"
   run_buildah 1 --debug=false rmi -a -p
-  is "$output" ".*when using the --all switch, you may not use --prune switch" "rmi -a -p"
+  expect_output --substring "when using the --all switch, you may not use --prune switch"
   buildah rmi --all
 }
 
@@ -150,7 +150,7 @@ load helpers
   expect_line_count 2
   run_buildah --debug=false rmi test3
   run_buildah --debug=false images -a -q
-  is "$output" "" "images -a -q"
+  expect_output ""
 }
 
 @test "rmi image that is created from another named image" {
diff --git a/tests/run.bats b/tests/run.bats
index 702dc31a383..02fcbdfaa1b 100644
--- a/tests/run.bats
+++ b/tests/run.bats
@@ -12,10 +12,10 @@ load helpers
 	root=$(buildah mount $cid)
 	buildah config --workingdir /tmp $cid
 	run_buildah --debug=false run $cid pwd
-	is "$output" "/tmp" "pwd"
+	expect_output "/tmp"
 	buildah config --workingdir /root $cid
 	run_buildah --debug=false run        $cid pwd
-	is "$output" "/root" "pwd"
+	expect_output "/root"
 	cp ${TESTDIR}/randomfile $root/tmp/
 	buildah run        $cid cp /tmp/randomfile /tmp/other-randomfile
 	test -s $root/tmp/other-randomfile
@@ -36,19 +36,19 @@ load helpers
 
 	# This should succeed, because buildah run stops caring at the --, which is preserved as part of the command.
 	run_buildah --debug=false run $cid echo -- -n test
-	is "$output" "-- -n test" "echo"
+	expect_output -- "-- -n test"
 
 	# This should succeed, because buildah run stops caring at the --, which is not part of the command.
 	run_buildah --debug=false run $cid -- echo -n -- test
-	is "$output" "-- test" "echo"
+	expect_output -- "-- test"
 
 	# This should succeed, because buildah run stops caring at the --.
 	run_buildah --debug=false run $cid -- echo -- -n test --
-	is "$output" "-- -n test --" "echo"
+	expect_output -- "-- -n test --"
 
 	# This should succeed, because buildah run stops caring at the --.
 	run_buildah --debug=false run $cid -- echo -n "test"
-	is "$output" "test" "echo"
+	expect_output "test"
 
 	buildah rm $cid
 }
@@ -67,57 +67,57 @@ load helpers
 	buildah config --entrypoint "" $cid
 	buildah config --cmd pwd $cid
 	run_buildah 1 --debug=false run $cid
-	is "$output" ".*command must be specified" "empty entrypoint, cmd, no args"
+	expect_output --substring "command must be specified" "empty entrypoint, cmd, no args"
 
 	# empty entrypoint, configured cmd, empty run arguments, end parsing option
 	buildah config --entrypoint "" $cid
 	buildah config --cmd pwd $cid
 	run_buildah 1 --debug=false run $cid --
-	is "$output" ".*command must be specified" "empty entrypoint, cmd, no args, --"
+	expect_output --substring "command must be specified" "empty entrypoint, cmd, no args, --"
 
 	# configured entrypoint, empty cmd, empty run arguments
 	buildah config --entrypoint pwd $cid
 	buildah config --cmd "" $cid
 	run_buildah 1 --debug=false run $cid
-	is "$output" ".*command must be specified" "entrypoint, empty cmd, no args"
+	expect_output --substring "command must be specified" "entrypoint, empty cmd, no args"
 
 	# configured entrypoint, empty cmd, empty run arguments, end parsing option
 	buildah config --entrypoint pwd $cid
 	buildah config --cmd "" $cid
 	run_buildah 1 --debug=false run $cid --
-	is "$output" ".*command must be specified" "entrypoint, empty cmd, no args, --"
+	expect_output --substring "command must be specified" "entrypoint, empty cmd, no args, --"
 
 	# configured entrypoint only, empty run arguments
 	buildah config --entrypoint pwd $cid
 	run_buildah 1 --debug=false run $cid
-	is "$output" ".*command must be specified" "entrypoint, no args"
+	expect_output --substring "command must be specified" "entrypoint, no args"
 
 	# configured entrypoint only, empty run arguments, end parsing option
 	buildah config --entrypoint pwd $cid
 	run_buildah 1 --debug=false run $cid --
-	is "$output" ".*command must be specified" "entrypoint, no args, --"
+	expect_output --substring "command must be specified" "entrypoint, no args, --"
 
 	# cofigured cmd only, empty run arguments
 	buildah config --cmd pwd $cid
 	run_buildah 1 --debug=false run $cid
-	is "$output" ".*command must be specified" "cmd, no args"
+	expect_output --substring "command must be specified" "cmd, no args"
 
 	# configured cmd only, empty run arguments, end parsing option
 	buildah config --cmd pwd $cid
 	run_buildah 1 --debug=false run $cid --
-	is "$output" ".*command must be specified" "cmd, no args, --"
+	expect_output --substring "command must be specified" "cmd, no args, --"
 
 	# configured entrypoint, configured cmd, empty run arguments
 	buildah config --entrypoint "pwd" $cid
 	buildah config --cmd "whoami" $cid
 	run_buildah 1 --debug=false run $cid
-	is "$output" ".*command must be specified" "entrypoint, cmd, no args"
+	expect_output --substring "command must be specified" "entrypoint, cmd, no args"
 
 	# configured entrypoint, configured cmd, empty run arguments, end parsing option
 	buildah config --entrypoint "pwd" $cid
 	buildah config --cmd "whoami" $cid
 	run_buildah 1 --debug=false run $cid --
-	is "$output" ".*command must be specified" "entrypoint, cmd, no args"
+	expect_output --substring "command must be specified"  "entrypoint, cmd, no args"
 
 
 	# Configured entrypoint/cmd shouldn't modify behaviour of run with argument
@@ -127,29 +127,29 @@ load helpers
 	buildah config --entrypoint "" $cid
 	buildah config --cmd "/invalid/cmd" $cid
 	run_buildah --debug=false run $cid -- pwd
-	is "$output" "/tmp" "empty entrypoint, invalid cmd, pwd"
+	expect_output "/tmp" "empty entrypoint, invalid cmd, pwd"
 
         # configured entrypoint, empty cmd, configured run arguments
         buildah config --entrypoint "/invalid/entrypoint" $cid
         buildah config --cmd "" $cid
         run_buildah --debug=false run $cid -- pwd
-	is "$output" "/tmp" "invalid entrypoint, empty cmd, pwd"
+	expect_output "/tmp" "invalid entrypoint, empty cmd, pwd"
 
         # configured entrypoint only, configured run arguments
         buildah config --entrypoint "/invalid/entrypoint" $cid
         run_buildah --debug=false run $cid -- pwd
-	is "$output" "/tmp" "invalid entrypoint, no cmd(??), pwd"
+	expect_output "/tmp" "invalid entrypoint, no cmd(??), pwd"
 
         # cofigured cmd only, configured run arguments
         buildah config --cmd "/invalid/cmd" $cid
         run_buildah --debug=false run $cid -- pwd
-	is "$output" "/tmp" "invalid cmd, no entrypoint(??), pwd"
+	expect_output "/tmp" "invalid cmd, no entrypoint(??), pwd"
 
         # configured entrypoint, configured cmd, configured run arguments
         buildah config --entrypoint "/invalid/entrypoint" $cid
         buildah config --cmd "/invalid/cmd" $cid
         run_buildah --debug=false run $cid -- pwd
-	is "$output" "/tmp" "invalid cmd & entrypoint, pwd"
+	expect_output "/tmp" "invalid cmd & entrypoint, pwd"
 
 	buildah rm $cid
 }
@@ -161,10 +161,10 @@ function configure_and_check_user() {
 
     run_buildah config -u "$setting" $cid
     run_buildah --debug=false run -- $cid id -u
-    is "$output" "$expect_u" "id -u ($setting)"
+    expect_output "$expect_u" "id -u ($setting)"
 
     run_buildah --debug=false run -- $cid id -g
-    is "$output" "$expect_g" "id -g ($setting)"
+    expect_output "$expect_g" "id -g ($setting)"
 }
 
 @test "run-user" {
@@ -201,15 +201,15 @@ function configure_and_check_user() {
 
         buildah config -u ${testbogususer} $cid
         run_buildah 1 --debug=false run -- $cid id -u
-        is "$output" ".*unknown user" "id -u (bogus user)"
+        expect_output --substring "unknown user" "id -u (bogus user)"
         run_buildah 1 --debug=false run -- $cid id -g
-        is "$output" ".*unknown user" "id -g (bogus user)"
+        expect_output --substring "unknown user" "id -g (bogus user)"
 
 	ln -vsf /etc/passwd $root/etc/passwd
 	buildah config -u ${testuser}:${testgroup} $cid
 	run_buildah 1 --debug=false run -- $cid id -u
 	echo "$output"
-	is "$output" ".*unknown user" "run as unknown user"
+	expect_output --substring "unknown user" "run as unknown user"
 
 	buildah unmount $cid
 	buildah rm $cid
@@ -227,7 +227,7 @@ function configure_and_check_user() {
 	run_buildah --debug=false run $cid hostname
 	[ "$output" != "foobar" ]
 	run_buildah --debug=false run --hostname foobar $cid hostname
-	is "$output" "foobar" "hostname"
+	expect_output "foobar"
 	buildah rm $cid
 }
 
@@ -298,23 +298,23 @@ function configure_and_check_user() {
 	fi
 	cid=$(buildah from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
 	run_buildah --debug=false run $cid awk '/open files/{print $4}' /proc/self/limits
-	is "$output" "1048576" "limits: open files (unlimited)"
+	expect_output "1048576" "limits: open files (unlimited)"
 	run_buildah --debug=false run $cid awk '/processes/{print $3}' /proc/self/limits
-	is "$output" "1048576" "limits: processes (unlimited)"
+	expect_output "1048576" "limits: processes (unlimited)"
 	buildah rm $cid
 
 	cid=$(buildah from --ulimit nofile=300:400 --pull --signature-policy ${TESTSDIR}/policy.json alpine)
 	run_buildah --debug=false run $cid awk '/open files/{print $4}' /proc/self/limits
-	is "$output" "300" "limits: open files (w/file limit)"
+	expect_output "300" "limits: open files (w/file limit)"
 	run_buildah --debug=false run $cid awk '/processes/{print $3}' /proc/self/limits
-	is "$output" "1048576" "limits: processes (w/file limit)"
+	expect_output "1048576" "limits: processes (w/file limit)"
 	buildah rm $cid
 
 	cid=$(buildah from --ulimit nproc=100:200 --ulimit nofile=300:400 --pull --signature-policy ${TESTSDIR}/policy.json alpine)
 	run_buildah --debug=false run $cid awk '/open files/{print $4}' /proc/self/limits
-	is "$output" "300" "limits: open files (w/file & proc limits)"
+	expect_output "300" "limits: open files (w/file & proc limits)"
 	run_buildah --debug=false run $cid awk '/processes/{print $3}' /proc/self/limits
-	is "$output" "100" "limits: processes (w/file & proc limits)"
+	expect_output "100" "limits: processes (w/file & proc limits)"
 	buildah rm $cid
 }
 
@@ -329,7 +329,7 @@ function configure_and_check_user() {
 	[ "$status" -ne 0 ]
 	# We'll create the mountpoint for "run".
 	run_buildah --debug=false run $cid ls -1 /var/lib
-        is "$output" ".*registry" "ls /var/lib"
+        expect_output --substring "registry"
 
 	# Double-check that the mountpoint is there.
 	test -d "$mnt"/var/lib/registry
diff --git a/tests/secrets.bats b/tests/secrets.bats
index 769328deb2b..4506003f83e 100644
--- a/tests/secrets.bats
+++ b/tests/secrets.bats
@@ -29,9 +29,9 @@ function teardown() {
     runc --version
     cid=$(buildah --default-mounts-file "$MOUNTS_PATH" --debug=false from --pull --signature-policy ${TESTSDIR}/policy.json alpine)
     run_buildah --debug=false run $cid ls /run/secrets
-    is "$output" ".*test.txt" "ls /run/secrets"
+    expect_output --substring "test.txt"
     run_buildah --debug run $cid ls /run/secrets/mysymlink
-    is "$output" ".*key.pem" "ls /run/secrets/mysymlink"
+    expect_output --substring "key.pem"
     buildah rm $cid
     rm -rf $TESTSDIR/containers
     rm -rf $TESTSDIR/rhel
diff --git a/tests/selinux.bats b/tests/selinux.bats
index 4d499e3476f..2ebe5ec4965 100644
--- a/tests/selinux.bats
+++ b/tests/selinux.bats
@@ -19,7 +19,7 @@ load helpers
 
   # Ensure that we label the same container consistently across multiple "run" instructions.
   run_buildah --debug=false run $cid sh -c 'tr \\0 \\n < /proc/self/attr/current'
-  is "$output" "$firstlabel" "label of second container == first"
+  expect_output "$firstlabel" "label of second container == first"
 
   # Ensure that different containers get different labels.
   cid1=$(buildah --debug=false from --quiet --signature-policy ${TESTSDIR}/policy.json $image)
@@ -46,7 +46,7 @@ load helpers
   # Create a container and read its context as a baseline.
   cid=$(buildah --debug=false from --security-opt label=disable --quiet --signature-policy ${TESTSDIR}/policy.json $image)
   run_buildah --debug=false run $cid sh -c 'tr \\0 \\n < /proc/self/attr/current'
-  is "$output" "$firstlabel" "container context matches our own"
+  expect_output "$firstlabel" "container context matches our own"
 }
 
 @test "selinux specific level" {
@@ -64,9 +64,9 @@ load helpers
 
   # Inspect image
   run_buildah --debug=false inspect  --format '{{.ProcessLabel}}' $cid
-  is "$output" $firstlabel "buildah inspect"
+  expect_output "$firstlabel"
 
   # Check actual running context
   run_buildah --debug=false run $cid sh -c 'tr \\0 \\n < /proc/self/attr/current'
-  is "$output" "$firstlabel" "running container context"
+  expect_output "$firstlabel" "running container context"
 }
diff --git a/tests/squash.bats b/tests/squash.bats
index 6f578c9d2b6..c938111adda 100644
--- a/tests/squash.bats
+++ b/tests/squash.bats
@@ -7,10 +7,11 @@ function check_lengths() {
   local image=$1
   local expect=$2
 
+  # matrix test: check given .Docker.* and .OCIv1.* fields in image
   for which in Docker OCIv1; do
     for field in RootFS.DiffIDs History; do
       run_buildah --debug=false inspect -t image -f "{{len .$which.$field}}" $image
-      is "$output" "$expect" "len(.$which.$field) ($image)"
+      expect_output "$expect"
     done
   done
 }