Add Go 1.20 errors.Join support

errutil/utilities.go

@@ -15,6 +15,7 @@
 package errutil
 
 import (
+	"github.com/cockroachdb/errors/join"
 	"github.com/cockroachdb/errors/secondary"
 	"github.com/cockroachdb/errors/withstack"
 	"github.com/cockroachdb/redact"
@@ -158,3 +159,10 @@ func WrapWithDepthf(depth int, err error, format string, args ...interface{}) er
 	err = withstack.WithStackDepth(err, depth+1)
 	return err
 }
+
+// JoinWithDepth constructs a Join error with the provided list of
+// errors as arguments, and wraps it in a `WithStackDepth` to capture a
+// stacktrace alongside.
+func JoinWithDepth(depth int, errs ...error) error {
+	return withstack.WithStackDepth(join.Join(errs...), depth+1)
+}

errutil_api.go

@@ -192,3 +192,19 @@ func HandleAsAssertionFailureDepth(depth int, origErr error) error {
 // - it also supports recursing through causes with Cause().
 // - if it detects an API use error, its panic object is a valid error.
 func As(err error, target interface{}) bool { return errutil.As(err, target) }
+
+// Join returns an error that wraps the given errors.
+// Any nil error values are discarded.
+// Join returns nil if errs contains no non-nil values.
+// The error formats as the concatenation of the strings obtained
+// by calling the Error method of each element of errs, with a newline
+// between each string. A stack trace is also retained.
+func Join(errs ...error) error {
+	return errutil.JoinWithDepth(1, errs...)
+}
+
+// JoinWithDepth is like Join but the depth at which the call stack is
+// captured can be specified.
+func JoinWithDepth(depth int, errs ...error) error {
+	return errutil.JoinWithDepth(depth+1, errs...)
+}

errutil_api_test.go

@@ -2,6 +2,7 @@ package errors_test
 
 import (
 	"fmt"
+	"strings"
 	"testing"
 
 	"github.com/cockroachdb/errors"
@@ -17,3 +18,14 @@ func TestUnwrap(t *testing.T) {
 	// (per API documentation)
 	tt.Check(errors.Unwrap(e) == nil)
 }
+
+// More detailed testing of Join is in datadriven_test.go. Here we make
+// sure that the public API includes the stacktrace wrapper.
+func TestJoin(t *testing.T) {
+	e := errors.Join(errors.New("abc123"), errors.New("def456"))
+	printed := fmt.Sprintf("%+v", e)
+	expected := `Error types: (1) *withstack.withStack (2) *join.joinError (3) *withstack.withStack (4) *errutil.leafError (5) *withstack.withStack (6) *errutil.leafError`
+	if !strings.Contains(printed, expected) {
+		t.Errorf("Expected: %s to contain: %s", printed, expected)
+	}
+}

fmttests/datadriven_test.go

@@ -37,6 +37,7 @@ import (
 	"github.com/cockroachdb/errors/errutil"
 	"github.com/cockroachdb/errors/hintdetail"
 	"github.com/cockroachdb/errors/issuelink"
+	"github.com/cockroachdb/errors/join"
 	"github.com/cockroachdb/errors/report"
 	"github.com/cockroachdb/errors/safedetails"
 	"github.com/cockroachdb/errors/secondary"
@@ -276,6 +277,9 @@ var wrapCommands = map[string]commandFn{
 		ctx = logtags.AddTag(ctx, "safe", redact.Safe(456))
 		return contexttags.WithContextTags(err, ctx)
 	},
+	"join": func(err error, args []arg) error {
+		return join.Join(err, errutil.New(strfy(args)))
+	},
 }
 
 var noPrefixWrappers = map[string]bool{
@@ -300,6 +304,7 @@ var noPrefixWrappers = map[string]bool{
 	"stack":             true,
 	"tags":              true,
 	"telemetry":         true,
+	"join":              true,
 }
 
 var wrapOnlyExceptions = map[string]string{}
@@ -329,6 +334,7 @@ func init() {
 		// means they don't match.
 		"nofmt",
 		"errorf",
+		"join",
 	} {
 		wrapOnlyExceptions[v] = `
 accept %\+v via Formattable.*IRREGULAR: not same as %\+v

fmttests/testdata/format/wrap-fmt

@@ -2251,6 +2251,197 @@ Type: "*fmttests.errFmt"
 Title: "×"
 (NO STACKTRACE)
 
+run
+fmt innerone innertwo
+join outerthree outerfour
+
+accept %\+v via Formattable.*IRREGULAR: not same as %\+v
+accept %\#v via Formattable.*IRREGULAR: not same as %\#v
+
+require (?s)
+----
+&join.joinError{
+    errs: {
+        &fmttests.errFmt{msg:"innerone\ninnertwo"},
+        &withstack.withStack{
+            cause: &errutil.leafError{msg:"outerthree\nouterfour"},
+            stack: &stack{...},
+        },
+    },
+}
+=====
+===== non-redactable formats
+=====
+== %#v
+&join.joinError{
+    errs: {
+        &fmttests.errFmt{msg:"innerone\ninnertwo"},
+        &withstack.withStack{
+            cause: &errutil.leafError{msg:"outerthree\nouterfour"},
+            stack: &stack{...},
+        },
+    },
+}
+== Error()
+innerone
+innertwo
+outerthree
+outerfour
+== %v = Error(), good
+== %s = Error(), good
+== %q = quoted Error(), good
+== %x = hex Error(), good
+== %X = HEX Error(), good
+== %+v
+innerone
+(1) innerone
+  | innertwo
+  | outerthree
+  | outerfour
+Wraps: (2) attached stack trace
+  -- stack trace:
+  | github.com/cockroachdb/errors/fmttests.glob...funcNN...
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/errors/fmttests.TestDatadriven.func2.1
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runDirective.func1
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runDirective
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runDirectiveOrSubTest
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runTestInternal
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.RunTest
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/errors/fmttests.TestDatadriven.func2
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.Walk
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.Walk.func1
+  | <tab><path>:<lineno>
+  | testing.tRunner
+  | <tab><path>:<lineno>
+  | runtime.goexit
+  | <tab><path>:<lineno>
+└─ Wraps: (3) outerthree
+  | outerfour
+Wraps: (4) innerone
+  | innertwo
+  | -- this is innerone
+  | innertwo's
+  | multi-line leaf payload
+Error types: (1) *join.joinError (2) *withstack.withStack (3) *errutil.leafError (4) *fmttests.errFmt
+== %#v via Formattable() = %#v, good
+== %v via Formattable() = Error(), good
+== %s via Formattable() = %v via Formattable(), good
+== %q via Formattable() = quoted %v via Formattable(), good
+== %+v via Formattable() == %+v, good
+=====
+===== redactable formats
+=====
+== printed via redact Print(), ok - congruent with %v
+‹innerone›
+‹innertwo›
+outerthree
+outerfour
+== printed via redact Printf() %v = Print(), good
+== printed via redact Printf() %s = Print(), good
+== printed via redact Printf() %q, refused - good
+== printed via redact Printf() %x, refused - good
+== printed via redact Printf() %X, refused - good
+== printed via redact Printf() %+v, ok - congruent with %+v
+‹innerone›
+(1) ‹innerone›
+  | ‹innertwo›
+  | outerthree
+  | outerfour
+Wraps: (2) attached stack trace
+  -- stack trace:
+  | github.com/cockroachdb/errors/fmttests.glob...funcNN...
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/errors/fmttests.TestDatadriven.func2.1
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runDirective.func1
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runDirective
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runDirectiveOrSubTest
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runTestInternal
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.RunTest
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/errors/fmttests.TestDatadriven.func2
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.Walk
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.Walk.func1
+  | <tab><path>:<lineno>
+  | testing.tRunner
+  | <tab><path>:<lineno>
+  | runtime.goexit
+  | <tab><path>:<lineno>
+└─ Wraps: (3) outerthree
+  | outerfour
+Wraps: (4) ‹innerone›
+‹  | innertwo›
+‹  | -- this is innerone›
+‹  | innertwo's›
+‹  | multi-line leaf payload›
+Error types: (1) *join.joinError (2) *withstack.withStack (3) *errutil.leafError (4) *fmttests.errFmt
+=====
+===== Sentry reporting
+=====
+== Message payload
+×
+(1) ×
+  | ×
+  | outerthree
+  | outerfour
+Wraps: (2) attached stack trace
+  -- stack trace:
+  | github.com/cockroachdb/errors/fmttests.glob...funcNN...
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/errors/fmttests.TestDatadriven.func2.1
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runDirective.func1
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runDirective
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runDirectiveOrSubTest
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.runTestInternal
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.RunTest
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/errors/fmttests.TestDatadriven.func2
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.Walk
+  | <tab><path>:<lineno>
+  | github.com/cockroachdb/datadriven.Walk.func1
+  | <tab><path>:<lineno>
+  | testing.tRunner
+  | <tab><path>:<lineno>
+  | runtime.goexit
+  | <tab><path>:<lineno>
+└─ Wraps: (3) outerthree
+  | outerfour
+Wraps: (4) ×
+×
+×
+×
+×
+Error types: (1) *join.joinError (2) *withstack.withStack (3) *errutil.leafError (4) *fmttests.errFmt
+-- report composition:
+*join.joinError
+== Extra "error types"
+github.com/cockroachdb/errors/join/*join.joinError (*::)
+== Exception 1 (Module: "error domain: <none>")
+Type: "*join.joinError"
+Title: "×"
+(NO STACKTRACE)
+
 run
 fmt innerone innertwo
 migrated outerthree outerfour