Reformat validation violation messages

... to improve readability.

Usability testing (#707) made clear that violation messages on a single
line are quite difficult to visually parse, making such error messages
less readable.

To support the reformatting, context is gathered at the time a violation
is detected. The message is formatted once all violations have
been collected.

Also includes minor improvements to "named" rule messages to improve
readability.

pkg/cmd/template/schema_consumer_test.go

@@ -1536,8 +1536,11 @@ foo: 0
 `
 		valuesYAML := `foo: 1`
 
-		expectedErrMsg := `One or more data values were invalid:
--  (schema.yaml:3) requires "foo > 2" (by schema.yaml:2)
+		expectedErrMsg := `Validating final data values:
+  (document)
+    from: schema.yaml:3
+    - must be: foo > 2 (by: schema.yaml:2)
+
 `
 		assertFailsWithSchemaAndDataValues(t, schemaYAML, valuesYAML, expectedErrMsg)
 	})
@@ -1549,8 +1552,11 @@ foo: 0
 `
 		valuesYAML := `foo: 1`
 
-		expectedErrMsg := `One or more data values were invalid:
-- .foo (values.yaml:1) requires "foo > 2" (by schema.yaml:3)
+		expectedErrMsg := `Validating final data values:
+  foo
+    from: values.yaml:1
+    - must be: foo > 2 (by: schema.yaml:3)
+
 `
 		assertFailsWithSchemaAndDataValues(t, schemaYAML, valuesYAML, expectedErrMsg)
 	})
@@ -1566,9 +1572,15 @@ foo:
 - 1
 `
 
-		expectedErrMsg := `One or more data values were invalid:
-- .foo[0] (values.yaml:2) requires "foo > 2" (by schema.yaml:4)
-- .foo[1] (values.yaml:3) requires "foo > 2" (by schema.yaml:4)
+		expectedErrMsg := `Validating final data values:
+  foo[0]
+    from: values.yaml:2
+    - must be: foo > 2 (by: schema.yaml:4)
+
+  foo[1]
+    from: values.yaml:3
+    - must be: foo > 2 (by: schema.yaml:4)
+
 `
 		assertFailsWithSchemaAndDataValues(t, schemaYAML, valuesYAML, expectedErrMsg)
 	})
@@ -1585,8 +1597,12 @@ bar: 0
 `
 		valuesYAML := ``
 
-		expectedErrMsg := `One or more data values were invalid:
-- .bar (schema.yaml:8) requires "not null"; fail: value is null (by schema.yaml:7)
+		expectedErrMsg := `Validating final data values:
+  bar
+    from: schema.yaml:8
+    - must be: not null (by: schema.yaml:7)
+      found: value is null
+
 `
 		assertFailsWithSchemaAndDataValues(t, schemaYAML, valuesYAML, expectedErrMsg)
 	})
@@ -1600,8 +1616,11 @@ foo: 0
 `
 		valuesYAML := `foo: 1`
 
-		expectedErrMsg := `One or more data values were invalid:
-- .foo (values.yaml:1) requires "foo > 2" (by schema.yaml:4)
+		expectedErrMsg := `Validating final data values:
+  foo
+    from: values.yaml:1
+    - must be: foo > 2 (by: schema.yaml:4)
+
 `
 		assertFailsWithSchemaAndDataValues(t, schemaYAML, valuesYAML, expectedErrMsg)
 	})
@@ -1622,8 +1641,11 @@ new: ""
 `
 			valuesYAML := `existing: foo`
 
-			expectedErrMsg := `One or more data values were invalid:
-- .new (schema.yaml:11) requires "non-empty" (by schema.yaml:10)
+			expectedErrMsg := `Validating final data values:
+  new
+    from: schema.yaml:11
+    - must be: non-empty (by: schema.yaml:10)
+
 `
 			assertFailsWithSchemaAndDataValues(t, schemaYAML, valuesYAML, expectedErrMsg)
 		})
@@ -1643,8 +1665,11 @@ existing: ""
 existing: foo
 `
 
-			expectedErrMsg := `One or more data values were invalid:
-- .existing (values.yaml:2) requires "a long string" (by schema.yaml:4)
+			expectedErrMsg := `Validating final data values:
+  existing
+    from: values.yaml:2
+    - must be: a long string (by: schema.yaml:4)
+
 `
 			assertFailsWithSchemaAndDataValues(t, schemaYAML, valuesYAML, expectedErrMsg)
 		})
@@ -1673,10 +1698,19 @@ bar:
 `
 
 		// none of the rules are from values.yml:
-		expectedErr := `One or more data values were invalid:
--  (schema.yml:3) requires "has 3 map items" (by schema.yml:2)
-- .foo (values.yml:5) requires "non-zero" (by schema.yml:4)
-- .bar (schema.yml:7) requires "has 2 items" (by schema.yml:6)
+		expectedErr := `Validating final data values:
+  (document)
+    from: schema.yml:3
+    - must be: has 3 map items (by: schema.yml:2)
+
+  foo
+    from: values.yml:5
+    - must be: non-zero (by: schema.yml:4)
+
+  bar
+    from: schema.yml:7
+    - must be: has 2 items (by: schema.yml:6)
+
 `
 
 		opts := &cmdtpl.Options{}
@@ -1702,11 +1736,23 @@ foo:
 - -1
 `
 
-		expectedErr := `One or more data values were invalid:
-- .foo[0] (values.yml:5) requires "non-zero" (by schema.yml:4)
-- .foo[0] (values.yml:5) requires "be odd" (by values.yml:4)
-- .foo[1] (values.yml:7) requires "non-zero" (by schema.yml:4)
-- .foo[1] (values.yml:7) requires "be even" (by values.yml:6)
+		expectedErr := `Validating final data values:
+  foo[0]
+    from: values.yml:5
+    - must be: non-zero (by: schema.yml:4)
+
+  foo[0]
+    from: values.yml:5
+    - must be: be odd (by: values.yml:4)
+
+  foo[1]
+    from: values.yml:7
+    - must be: non-zero (by: schema.yml:4)
+
+  foo[1]
+    from: values.yml:7
+    - must be: be even (by: values.yml:6)
+
 `
 
 		opts := &cmdtpl.Options{}

pkg/validations/filetests/all-rules-are-run.tpltest

@@ -6,8 +6,16 @@ config: [1,1]
 +++
 
 ERR:
-- .config (stdin:4) requires "custom rule"; fail: fails (by stdin:3)
-- .config (stdin:4) requires "length greater or equal to 10"; fail: length of 2 is less than 10 (by stdin:3)
-- .config (stdin:4) requires "length less than or equal to 1"; fail: length of 2 is more than 1 (by stdin:3)
-- .config (stdin:4) requires "a value greater or equal to [2, 2]"; fail: value is less than [2, 2] (by stdin:3)
-- .config (stdin:4) requires "a value less than or equal to [0, 0]"; fail: value is more than [0, 0] (by stdin:3)
+  config
+    from: stdin:4
+    - must be: custom rule (by: stdin:3)
+      found: fails
+    - must be: length >= 10 (by: stdin:3)
+      found: length = 2
+    - must be: length <= 1 (by: stdin:3)
+      found: length = 2
+    - must be: a value >= [2, 2] (by: stdin:3)
+      found: value < [2, 2]
+    - must be: a value <= [0, 0] (by: stdin:3)
+      found: value > [0, 0]
+

pkg/validations/filetests/max=/invalid-when-value-greater-than-max.tpltest

@@ -4,4 +4,8 @@ foo: 11
 +++
 
 ERR:
-- .foo (stdin:2) requires "a value less than or equal to 10"; fail: value is more than 10 (by stdin:1)
+  foo
+    from: stdin:2
+    - must be: a value <= 10 (by: stdin:1)
+      found: value > 10
+

pkg/validations/filetests/max=/rejects-non-comparable-constraint.tpltest

@@ -5,4 +5,8 @@ value:
 +++
 
 ERR:
-- .value (stdin:2) requires "a value less than or equal to {\"foo\": True}"; dict <= dict not implemented (by stdin:1)
+  value
+    from: stdin:2
+    - must be: a value <= {"foo": True} (by: stdin:1)
+      found: dict <= dict not implemented
+

pkg/validations/filetests/max=/rejects-non-comparable-value.tpltest

@@ -6,4 +6,8 @@ value:
 +++
 
 ERR:
-- .value (stdin:2) requires "a value less than or equal to 4"; dict <= int not implemented (by stdin:1)
+  value
+    from: stdin:2
+    - must be: a value <= 4 (by: stdin:1)
+      found: dict <= int not implemented
+

pkg/validations/filetests/max_len=/invalid-when-length-greater-than-max.tpltest

@@ -4,4 +4,8 @@ value: "123456"
 +++
 
 ERR:
-- .value (stdin:2) requires "length less than or equal to 5"; fail: length of 6 is more than 5 (by stdin:1)
+  value
+    from: stdin:2
+    - must be: length <= 5 (by: stdin:1)
+      found: length = 6
+

pkg/validations/filetests/max_len=/works-with-int-and-float

@@ -6,5 +6,13 @@ bar: "longer than 10"
 +++
 
 ERR:
-- .foo (stdin:2) requires "length less than or equal to 10"; fail: length of 14 is more than 10 (by stdin:1)
-- .bar (stdin:4) requires "length less than or equal to 10"; fail: length of 14 is more than 10 (by stdin:3)
+  foo
+    from: stdin:2
+    - must be: length <= 10 (by: stdin:1)
+      found: length = 14
+
+  bar
+    from: stdin:4
+    - must be: length <= 10 (by: stdin:3)
+      found: length = 14
+

pkg/validations/filetests/min=/invalid-when-value-less-than-min.tpltest

@@ -4,4 +4,8 @@ value: 9
 +++
 
 ERR:
-- .value (stdin:2) requires "a value greater or equal to 10"; fail: value is less than 10 (by stdin:1)
+  value
+    from: stdin:2
+    - must be: a value >= 10 (by: stdin:1)
+      found: value < 10
+

pkg/validations/filetests/min=/rejects-non-comparable-constraint.tpltest

@@ -5,4 +5,8 @@ value:
 +++
 
 ERR:
-- .value (stdin:2) requires "a value greater or equal to {\"foo\": True}"; dict >= dict not implemented (by stdin:1)
+  value
+    from: stdin:2
+    - must be: a value >= {"foo": True} (by: stdin:1)
+      found: dict >= dict not implemented
+

pkg/validations/filetests/min=/rejects-non-comparable-value.tpltest

@@ -6,4 +6,8 @@ value:
 +++
 
 ERR:
-- .value (stdin:2) requires "a value greater or equal to 4"; dict >= int not implemented (by stdin:1)
+  value
+    from: stdin:2
+    - must be: a value >= 4 (by: stdin:1)
+      found: dict >= int not implemented
+

pkg/validations/filetests/min_len=/invalid-when-length-is-less-than-min.tpltest

@@ -4,4 +4,8 @@ value: "1234"
 +++
 
 ERR:
-- .value (stdin:2) requires "length greater or equal to 5"; fail: length of 4 is less than 5 (by stdin:1)
+  value
+    from: stdin:2
+    - must be: length >= 5 (by: stdin:1)
+      found: length = 4
+

pkg/validations/filetests/min_len=/works-with-int-and-float.tpltest

@@ -6,5 +6,13 @@ bar: "shorter than 20"
 +++
 
 ERR:
-- .foo (stdin:2) requires "length greater or equal to 20"; fail: length of 15 is less than 20 (by stdin:1)
-- .bar (stdin:4) requires "length greater or equal to 20"; fail: length of 15 is less than 20 (by stdin:3)
+  foo
+    from: stdin:2
+    - must be: length >= 20 (by: stdin:1)
+      found: length = 15
+
+  bar
+    from: stdin:4
+    - must be: length >= 20 (by: stdin:3)
+      found: length = 15
+

pkg/validations/filetests/not_null=/invalid-when-value-is-null.tpltest

@@ -4,4 +4,8 @@ value: null
 +++
 
 ERR:
-- .value (stdin:2) requires "not null"; fail: value is null (by stdin:1)
+  value
+    from: stdin:2
+    - must be: not null (by: stdin:1)
+      found: value is null
+

pkg/validations/filetests/not_null=/when-value-is-null-short-circuits-other-rules.tpltest

@@ -4,4 +4,8 @@ value: null
 +++
 
 ERR:
-- .value (stdin:2) requires "not null"; fail: value is null (by stdin:1)
+  value
+    from: stdin:2
+    - must be: not null (by: stdin:1)
+      found: value is null
+

pkg/validations/filetests/one_not_null=/invalid-when-more-than-one-is-not-null.tpltest

@@ -6,4 +6,8 @@ config:
 +++
 
 ERR:
-- .config (stdin:2) requires "exactly one child not null"; check: multiple values are not null ["foo" "bar"] (by stdin:1)
+  config
+    from: stdin:2
+    - must be: exactly one of all children to be not null (by: stdin:1)
+      found: ["foo", "bar"] are not null
+

pkg/validations/filetests/one_of=/invalid-when-value-not-in-enum.tpltest

@@ -4,4 +4,8 @@ foo: critical
 +++
 
 ERR:
-- .foo (stdin:2) requires "one of"; fail: value not in ["debug", "info", "warning", "error", "fatal"] (by stdin:1)
+  foo
+    from: stdin:2
+    - must be: one of ["debug", "info", "warning", "error", "fatal"] (by: stdin:1)
+      found: not one of allowed values
+

pkg/validations/filetests/when-null-skips/value-is-null-with-not_null--runs-rules.tpltest

@@ -0,0 +1,11 @@
+#@assert/validate not_null=True
+foo: null
+
++++
+
+ERR:
+  foo
+    from: stdin:2
+    - must be: not null (by: stdin:1)
+      found: value is null
+

pkg/validations/filetests/when-null-skips/value-not-null--runs-rules.tpltest

@@ -0,0 +1,11 @@
+#@assert/validate ("", lambda v: fail("rules were run"))
+foo: ""
+
++++
+
+ERR:
+  foo
+    from: stdin:2
+    - must be:  (by: stdin:1)
+      found: rules were run
+

pkg/validations/filetests/when=/can-use-parent-value.tpltest

@@ -8,4 +8,8 @@ counters:
 +++
 
 ERR:
-- .counters.foo (stdin:4) requires "fail"; fail: fails (by stdin:3)
+  counters.foo
+    from: stdin:4
+    - must be: fail (by: stdin:3)
+      found: fails
+

pkg/validations/filetests/when=/can-use-root-value.tpltest

@@ -8,4 +8,8 @@ counters:
 +++
 
 ERR:
-- .counters.bar (stdin:6) requires "fail"; fail: fails (by stdin:5)
+  counters.bar
+    from: stdin:6
+    - must be: fail (by: stdin:5)
+      found: fails
+

pkg/validations/filetests/when=/rejects-callable-arg-failing.tpltest

@@ -6,4 +6,4 @@ foo: bar
 +++
 
 ERR:
-Validating .foo: Failure evaluating when=: fail: error from within lambda
+Validating foo: Failure evaluating when=: fail: error from within lambda

pkg/validations/filetests/when=/rejects-callable-arg-returns-non-bool.tpltest

@@ -4,4 +4,4 @@ foo: bar
 +++
 
 ERR:
-Validating .foo: want when= to be bool, got string
+Validating foo: want when= to be bool, got string