cmd/go: run 'go help documentation' through gofmt in TestDocsUpToDate

mkalldocs.sh runs gofmt on the output, but the test does not.
If go help documentation and gofmt disagree, the test will fail.
Fix that.

Change-Id: I837374a2d36cb5d71278ecefe2a7b6544622c576
Reviewed-on: https://go-review.googlesource.com/c/go/+/384256
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/cmd/go/help_test.go b/src/cmd/go/help_test.go
index abfc3db9936bb909dc180026506a0090fdc58a16..3e1d817ca5b236bf4954c1c3f3fd1d6811ec92cd 100644 (file)
--- a/src/cmd/go/help_test.go
+++ b/src/cmd/go/help_test.go
@@ -6,6 +6,8 @@ package main_test
 
 import (
        "bytes"
+       "go/format"
+       diffpkg "internal/diff"
        "os"
        "testing"
 
@@ -23,11 +25,17 @@ func TestDocsUpToDate(t *testing.T) {
        buf := new(bytes.Buffer)
        // Match the command in mkalldocs.sh that generates alldocs.go.
        help.Help(buf, []string{"documentation"})
-       data, err := os.ReadFile("alldocs.go")
+       internal := buf.Bytes()
+       internal, err := format.Source(internal)
+       if err != nil {
+               t.Fatalf("gofmt docs: %v", err)
+       }
+       alldocs, err := os.ReadFile("alldocs.go")
        if err != nil {
                t.Fatalf("error reading alldocs.go: %v", err)
        }
-       if !bytes.Equal(data, buf.Bytes()) {
-               t.Errorf("alldocs.go is not up to date; run mkalldocs.sh to regenerate it")
+       if !bytes.Equal(internal, alldocs) {
+               t.Errorf("alldocs.go is not up to date; run mkalldocs.sh to regenerate it\n%s",
+                       diffpkg.Diff("go help documentation | gofmt", internal, "alldocs.go", alldocs))
        }
 }