cmd/go: replace the 'addcrlf' script command with a more general 'replace' command

This allows the "reuse_git" test to avoid depending on exact JSON
blobs, which will be important when the URLs start referring to
test-local vcweb servers.

For #27494.

Change-Id: I22fde5110b3267b8fb9fb9c59fabc3b8a8b492c8
Reviewed-on: https://go-review.googlesource.com/c/go/+/427094
Reviewed-by: Russ Cox <rsc@golang.org>
Auto-Submit: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Bryan Mills <bcmills@google.com>

5 files changed, 55 insertions, 99 deletions

diff --git a/src/cmd/go/internal/script/cmds.go b/src/cmd/go/internal/script/cmds.go
index c0bd31ed65..9fb092e0d8 100644
--- a/src/cmd/go/internal/script/cmds.go
+++ b/src/cmd/go/internal/script/cmds.go
@@ -43,6 +43,7 @@ func DefaultCmds() map[string]Cmd {
 		"mkdir":   Mkdir(),
 		"mv":      Mv(),
 		"rm":      Rm(),
+		"replace": Replace(),
 		"sleep":   Sleep(),
 		"stderr":  Stderr(),
 		"stdout":  Stdout(),
@@ -867,6 +868,43 @@ func Program(name string, interrupt os.Signal, gracePeriod time.Duration) Cmd {
 		})
 }
 
+// Replace replaces all occurrences of a string in a file with another string.
+func Replace() Cmd {
+	return Command(
+		CmdUsage{
+			Summary: "replace strings in a file",
+			Args:    "[old new]... file",
+			Detail: []string{
+				"The 'old' and 'new' arguments are unquoted as if in quoted Go strings.",
+			},
+		},
+		func(s *State, args ...string) (WaitFunc, error) {
+			if len(args)%2 != 1 {
+				return nil, ErrUsage
+			}
+
+			oldNew := make([]string, 0, len(args)-1)
+			for _, arg := range args[:len(args)-1] {
+				s, err := strconv.Unquote(`"` + arg + `"`)
+				if err != nil {
+					return nil, err
+				}
+				oldNew = append(oldNew, s)
+			}
+
+			r := strings.NewReplacer(oldNew...)
+			file := s.Path(args[len(args)-1])
+
+			data, err := os.ReadFile(file)
+			if err != nil {
+				return nil, err
+			}
+			replaced := r.Replace(string(data))
+
+			return nil, os.WriteFile(file, []byte(replaced), 0666)
+		})
+}
+
 // Rm removes a file or directory.
 //
 // If a directory, Rm also recursively removes that directory's
diff --git a/src/cmd/go/scriptcmds_test.go b/src/cmd/go/scriptcmds_test.go
index a0cbafb8ea..2a9900782b 100644
--- a/src/cmd/go/scriptcmds_test.go
+++ b/src/cmd/go/scriptcmds_test.go
@@ -5,7 +5,6 @@
 package main_test
 
 import (
-	"bytes"
 	"cmd/go/internal/script"
 	"cmd/go/internal/script/scripttest"
 	"cmd/go/internal/work"
@@ -30,7 +29,6 @@ func scriptCommands(interrupt os.Signal, gracePeriod time.Duration) map[string]s
 		cmds[name] = cmd
 	}
 
-	add("addcrlf", scriptAddCRLF())
 	add("cc", scriptCC(cmdExec))
 	cmdGo := scriptGo(interrupt, gracePeriod)
 	add("go", cmdGo)
@@ -39,34 +37,6 @@ func scriptCommands(interrupt os.Signal, gracePeriod time.Duration) map[string]s
 	return cmds
 }
 
-// scriptAddCRLF adds CRLF line endings to the named files.
-func scriptAddCRLF() script.Cmd {
-	return script.Command(
-		script.CmdUsage{
-			Summary: "convert line endings to CRLF",
-			Args:    "file...",
-		},
-		func(s *script.State, args ...string) (script.WaitFunc, error) {
-			if len(args) == 0 {
-				return nil, script.ErrUsage
-			}
-
-			for _, file := range args {
-				file = s.Path(file)
-				data, err := os.ReadFile(file)
-				if err != nil {
-					return nil, err
-				}
-				err = os.WriteFile(file, bytes.ReplaceAll(data, []byte("\n"), []byte("\r\n")), 0666)
-				if err != nil {
-					return nil, err
-				}
-			}
-
-			return nil, nil
-		})
-}
-
 // scriptCC runs the C compiler along with platform specific options.
 func scriptCC(cmdExec script.Cmd) script.Cmd {
 	return script.Command(
diff --git a/src/cmd/go/testdata/script/README b/src/cmd/go/testdata/script/README
index b3902eded5..58c9170d5d 100644
--- a/src/cmd/go/testdata/script/README
+++ b/src/cmd/go/testdata/script/README
@@ -204,10 +204,6 @@ for manual debugging of failing tests:
 	$
 
 The available commands are:
-addcrlf file...
-	convert line endings to CRLF
-
-
 cat files...
 	concatenate files and print to the script's stdout buffer
 
@@ -304,6 +300,12 @@ mv old new
 	OS-specific restrictions may apply when old and new are in
 	different directories.
 
+replace [old new]... file
+	replace strings in a file
+
+	The 'old' and 'new' arguments are unquoted as if in quoted
+	Go strings.
+
 rm path...
 	remove a file or directory
 
diff --git a/src/cmd/go/testdata/script/mod_find.txt b/src/cmd/go/testdata/script/mod_find.txt
index 1e01973ff4..9c2037b6e0 100644
--- a/src/cmd/go/testdata/script/mod_find.txt
+++ b/src/cmd/go/testdata/script/mod_find.txt
@@ -8,7 +8,7 @@ stderr 'module x'
 
 # Import comment works even with CRLF line endings.
 rm go.mod
-addcrlf x.go
+replace '\n' '\r\n' x.go
 go mod init
 stderr 'module x'
 
diff --git a/src/cmd/go/testdata/script/reuse_git.txt b/src/cmd/go/testdata/script/reuse_git.txt
index 8c23bde49b..8df47541be 100644
--- a/src/cmd/go/testdata/script/reuse_git.txt
+++ b/src/cmd/go/testdata/script/reuse_git.txt
@@ -321,6 +321,8 @@ stdout '"Reuse": true'
 ! stdout '"(Dir|Info|GoMod|Zip)"'
 
 # reuse attempt with stale hash should reinvoke git, not report reuse
+cp tagtestsv022.json tagtestsv022badhash.json
+replace '57952' '56952XXX' tagtestsv022badhash.json
 go mod download -reuse=tagtestsv022badhash.json -x -json vcs-test.golang.org/git/tagtests.git@v0.2.2
 stderr 'git fetch'
 ! stdout '"Reuse": true'
@@ -337,6 +339,8 @@ stdout '"GoMod"'
 stdout '"Zip"'
 
 # reuse with stale repo URL
+cp tagtestsv022.json tagtestsv022badurl.json
+replace 'git/tagtests\"' 'git/tagtestsXXX\"' tagtestsv022badurl.json
 go mod download -reuse=tagtestsv022badurl.json -x -json vcs-test.golang.org/git/tagtests.git@v0.2.2
 ! stdout '"Reuse": true'
 stdout '"URL": "https://vcs-test.golang.org/git/tagtests"'
@@ -346,80 +350,22 @@ stdout '"GoMod"'
 stdout '"Zip"'
 
 # reuse with stale VCS
+cp tagtestsv022.json tagtestsv022badvcs.json
+replace '\"git\"' '\"gitXXX\"' tagtestsv022badvcs.json
 go mod download -reuse=tagtestsv022badvcs.json -x -json vcs-test.golang.org/git/tagtests.git@v0.2.2
 ! stdout '"Reuse": true'
 stdout '"URL": "https://vcs-test.golang.org/git/tagtests"'
 
 # reuse with stale Dir
+cp tagtestsv022.json tagtestsv022baddir.json
+replace '\t\t\"Ref\":' '\t\t\"Subdir\": \"subdir\",\n\t\t\"Ref\":' tagtestsv022baddir.json
 go mod download -reuse=tagtestsv022baddir.json -x -json vcs-test.golang.org/git/tagtests.git@v0.2.2
 ! stdout '"Reuse": true'
 stdout '"URL": "https://vcs-test.golang.org/git/tagtests"'
 
 # reuse with stale TagSum
+cp tagtests.json tagtestsbadtagsum.json
+replace 'sMEOGo=' 'sMEoGo=XXX' tagtestsbadtagsum.json
 go mod download -reuse=tagtestsbadtagsum.json -x -json vcs-test.golang.org/git/tagtests.git@latest
 ! stdout '"Reuse": true'
 stdout '"TagSum": "t1:Dp7yRKDuE8WjG0429PN9hYWjqhy2te7P9Oki/sMEOGo="'
-
--- tagtestsv022badhash.json --
-{
-	"Path": "vcs-test.golang.org/git/tagtests.git",
-	"Version": "v0.2.2",
-	"Origin": {
-		"VCS": "git",
-		"URL": "https://vcs-test.golang.org/git/tagtests",
-		"Ref": "refs/tags/v0.2.2",
-		"Hash": "59356c8cd18c5fe9a598167d98a6843e52d57952XXX"
-	}
-}
-
--- tagtestsbadtagsum.json --
-{
-	"Path": "vcs-test.golang.org/git/tagtests.git",
-	"Version": "v0.2.2",
-	"Query": "latest",
-	"Origin": {
-		"VCS": "git",
-		"URL": "https://vcs-test.golang.org/git/tagtests",
-		"TagSum": "t1:Dp7yRKDuE8WjG0429PN9hYWjqhy2te7P9Oki/sMEOGo=XXX",
-		"Ref": "refs/tags/v0.2.2",
-		"Hash": "59356c8cd18c5fe9a598167d98a6843e52d57952"
-	},
-	"Reuse": true
-}
-
--- tagtestsv022badvcs.json --
-{
-	"Path": "vcs-test.golang.org/git/tagtests.git",
-	"Version": "v0.2.2",
-	"Origin": {
-		"VCS": "gitXXX",
-		"URL": "https://vcs-test.golang.org/git/tagtests",
-		"Ref": "refs/tags/v0.2.2",
-		"Hash": "59356c8cd18c5fe9a598167d98a6843e52d57952"
-	}
-}
-
--- tagtestsv022baddir.json --
-{
-	"Path": "vcs-test.golang.org/git/tagtests.git",
-	"Version": "v0.2.2",
-	"Origin": {
-		"VCS": "git",
-		"URL": "https://vcs-test.golang.org/git/tagtests",
-		"Subdir": "subdir",
-		"Ref": "refs/tags/v0.2.2",
-		"Hash": "59356c8cd18c5fe9a598167d98a6843e52d57952"
-	}
-}
-
--- tagtestsv022badurl.json --
-{
-	"Path": "vcs-test.golang.org/git/tagtests.git",
-	"Version": "v0.2.2",
-	"Origin": {
-		"VCS": "git",
-		"URL": "https://vcs-test.golang.org/git/tagtestsXXX",
-		"Ref": "refs/tags/v0.2.2",
-		"Hash": "59356c8cd18c5fe9a598167d98a6843e52d57952"
-	}
-}