cmd/fix: add modernize and inline analyzers

We ran 'go mod vendor' to pull in the newly used packages.

Also, add a cmd/go script test that minimally
exercises each analyzer, analogous to the cmd/vet test.

For #75266
For #75267
For #71859

Change-Id: I334daea048e3d2f614a1788292a3175acf173932
Reviewed-on: https://go-review.googlesource.com/c/go/+/710995
Reviewed-by: Michael Matloob <matloob@golang.org>
Auto-Submit: Alan Donovan <adonovan@google.com>
TryBot-Bypass: Alan Donovan <adonovan@google.com>
Reviewed-by: Michael Matloob <matloob@google.com>

Author: adonovan

src/cmd/fix/main.go

@@ -22,10 +22,13 @@ package main
 import (
 	"cmd/internal/objabi"
 	"cmd/internal/telemetry/counter"
+	"slices"
 
 	"golang.org/x/tools/go/analysis"
 	"golang.org/x/tools/go/analysis/passes/buildtag"
 	"golang.org/x/tools/go/analysis/passes/hostport"
+	"golang.org/x/tools/go/analysis/passes/inline"
+	"golang.org/x/tools/go/analysis/passes/modernize"
 	"golang.org/x/tools/go/analysis/unitchecker"
 )
 
@@ -38,22 +41,23 @@ func main() {
 	unitchecker.Main(suite...) // (never returns)
 }
 
-// The fix suite analyzers produce fixes that are safe to apply.
-// (Diagnostics may not describe actual problems,
-// but their fixes must be unambiguously safe to apply.)
-var suite = []*analysis.Analyzer{
-	buildtag.Analyzer,
-	hostport.Analyzer,
-	// TODO(adonovan): now the modernize (proposal #75266) and
-	// inline (proposal #75267) analyzers are published, revendor
-	// x/tools and add them here.
-	//
-	// TODO(adonovan):add any other vet analyzers whose fixes are always safe.
+// The fix suite analyzers produce fixes are unambiguously safe to apply,
+// even if the diagnostics might not describe actual problems.
+var suite = slices.Concat(
+	[]*analysis.Analyzer{
+		buildtag.Analyzer,
+		hostport.Analyzer,
+		inline.Analyzer,
+	},
+	modernize.Suite,
+	// TODO(adonovan): add any other vet analyzers whose fixes are always safe.
 	// Candidates to audit: sigchanyzer, printf, assign, unreachable.
+	// Many of staticcheck's analyzers would make good candidates
+	//   (e.g. rewriting WriteString(fmt.Sprintf()) to Fprintf.)
 	// Rejected:
 	// - composites: some types (e.g. PointXY{1,2}) don't want field names.
 	// - timeformat: flipping MM/DD is a behavior change, but the code
 	//    could potentially be a workaround for another bug.
 	// - stringintconv: offers two fixes, user input required to choose.
 	// - fieldalignment: poor signal/noise; fix could be a regression.
-}
+)

src/cmd/go/testdata/script/fix_suite.txt

@@ -0,0 +1,53 @@
+# Elementary test of each analyzer in the "go fix" suite.
+# This is simply to prove that they are running at all;
+# detailed behavior is tested in x/tools.
+#
+# Each assertion matches the expected diff.
+#
+# Tip: to see the actual stdout,
+# temporarily prefix the go command with "! ".
+
+go fix -diff example.com/x
+
+# buildtag
+stdout '-// \+build go1.26'
+
+# hostport
+stdout 'net.Dial.*net.JoinHostPort'
+
+# inline
+stdout 'var three = 1 \+ 2'
+
+# newexpr (proxy for whole modernize suite)
+stdout 'var _ = new\(123\)'
+
+-- go.mod --
+module example.com/x
+go 1.26
+
+-- x.go --
+//go:build go1.26
+// +build go1.26
+
+// ↑ buildtag
+
+package x
+
+import (
+	"fmt"
+	"net"
+)
+
+// hostport
+var s string
+var _, _ = net.Dial("tcp", fmt.Sprintf("%s:%d", s, 80))
+
+//go:fix inline
+func add(x, y int) int { return x + y }
+
+// inline
+var three = add(1, 2)
+
+// newexpr
+func varOf(x int) *int { return &x }
+var _ = varOf(123)