feat: check if go.mod has replace directives

closes #4395

internal/pipe/gomod/gomod_proxy.go

@@ -10,14 +10,64 @@ import (
 	"os/exec"
 	"path"
 	"path/filepath"
+	"regexp"
 	"strings"
 
 	"github.com/caarlos0/log"
+	"github.com/goreleaser/goreleaser/internal/logext"
 	"github.com/goreleaser/goreleaser/internal/tmpl"
 	"github.com/goreleaser/goreleaser/pkg/config"
 	"github.com/goreleaser/goreleaser/pkg/context"
 )
 
+// ErrReplaceWithProxy happens when the configuration has gomod.proxy enabled,
+// and the go.mod file contains replace directives.
+//
+// Replaces does not work with proxying, nor with go installs,
+// and are made for development only.
+var ErrReplaceWithProxy = errors.New("cannot use the go.mod replace directive with go mod proxy enabled")
+
+type CheckGoModPipe struct{}
+
+func (CheckGoModPipe) String() string { return "checking go.mod" }
+func (CheckGoModPipe) Skip(ctx *context.Context) bool {
+	return ctx.ModulePath == "" || !ctx.Config.GoMod.Proxy
+}
+
+var replaceRe = regexp.MustCompile("^replace .* => .*$")
+
+// Run the ReplaceCheckPipe.
+func (CheckGoModPipe) Run(ctx *context.Context) error {
+	for i := range ctx.Config.Builds {
+		build := &ctx.Config.Builds[i]
+		path := filepath.Join(build.UnproxiedDir, "go.mod")
+		mod, err := os.ReadFile(path)
+		if err != nil {
+			log.Errorf("could not check %q", path)
+			return nil
+		}
+		for _, line := range strings.Split(string(mod), "\n") {
+			if !replaceRe.MatchString(line) {
+				continue
+			}
+			log.Warnf(
+				"your %[2]s file has %[1]s directive in it, and go mod proxying is enabled - "+
+					"this does not work, and you need to either disable it or remove the %[1]s directive",
+				logext.Keyword("replace"),
+				logext.Keyword("go.mod"),
+			)
+			log.Warnf("the offending line is %s", logext.Keyword(strings.TrimSpace(line)))
+			if ctx.Snapshot {
+				// only warn on snapshots
+				break
+			}
+			return ErrReplaceWithProxy
+		}
+	}
+
+	return nil
+}
+
 // ProxyPipe for gomod proxy.
 type ProxyPipe struct{}
 

internal/pipe/gomod/gomod_proxy_test.go

@@ -3,6 +3,7 @@ package gomod
 import (
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"runtime"
 	"syscall"
@@ -15,6 +16,62 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestString(t *testing.T) {
+	require.NotEmpty(t, CheckGoModPipe{}.String())
+	require.NotEmpty(t, ProxyPipe{}.String())
+}
+
+func TestCheckGoMod(t *testing.T) {
+	t.Run("replace on snapshot", func(t *testing.T) {
+		dir := testlib.Mktmp(t)
+		dist := filepath.Join(dir, "dist")
+		ctx := testctx.NewWithCfg(config.Project{
+			Dist: dist,
+			GoMod: config.GoMod{
+				Proxy:    true,
+				GoBinary: "go",
+			},
+			Builds: []config.Build{
+				{
+					ID:     "foo",
+					Goos:   []string{runtime.GOOS},
+					Goarch: []string{runtime.GOARCH},
+					Main:   ".",
+					Dir:    ".",
+				},
+			},
+		}, testctx.Snapshot, withGoReleaserModulePath)
+
+		fakeGoModAndSum(t, ctx.ModulePath)
+		require.NoError(t, exec.Command("go", "mod", "edit", "-replace", "foo=../bar").Run())
+		require.NoError(t, CheckGoModPipe{}.Run(ctx))
+	})
+	t.Run("replace", func(t *testing.T) {
+		dir := testlib.Mktmp(t)
+		dist := filepath.Join(dir, "dist")
+		ctx := testctx.NewWithCfg(config.Project{
+			Dist: dist,
+			GoMod: config.GoMod{
+				Proxy:    true,
+				GoBinary: "go",
+			},
+			Builds: []config.Build{
+				{
+					ID:     "foo",
+					Goos:   []string{runtime.GOOS},
+					Goarch: []string{runtime.GOARCH},
+					Main:   ".",
+					Dir:    ".",
+				},
+			},
+		}, withGoReleaserModulePath)
+
+		fakeGoModAndSum(t, ctx.ModulePath)
+		require.NoError(t, exec.Command("go", "mod", "edit", "-replace", "foo=../bar").Run())
+		require.ErrorIs(t, CheckGoModPipe{}.Run(ctx), ErrReplaceWithProxy)
+	})
+}
+
 func TestGoModProxy(t *testing.T) {
 	t.Run("goreleaser", func(t *testing.T) {
 		dir := testlib.Mktmp(t)
@@ -167,7 +224,9 @@ func TestProxyDescription(t *testing.T) {
 
 func TestSkip(t *testing.T) {
 	t.Run("skip false gomod.proxy", func(t *testing.T) {
-		require.True(t, ProxyPipe{}.Skip(testctx.New()))
+		ctx := testctx.New()
+		require.True(t, ProxyPipe{}.Skip(ctx))
+		require.True(t, CheckGoModPipe{}.Skip(ctx))
 	})
 
 	t.Run("skip snapshot", func(t *testing.T) {
@@ -177,6 +236,7 @@ func TestSkip(t *testing.T) {
 			},
 		}, withGoReleaserModulePath, testctx.Snapshot)
 		require.True(t, ProxyPipe{}.Skip(ctx))
+		require.False(t, CheckGoModPipe{}.Skip(ctx))
 	})
 
 	t.Run("skip not a go module", func(t *testing.T) {
@@ -186,6 +246,7 @@ func TestSkip(t *testing.T) {
 			},
 		}, func(ctx *context.Context) { ctx.ModulePath = "" })
 		require.True(t, ProxyPipe{}.Skip(ctx))
+		require.True(t, CheckGoModPipe{}.Skip(ctx))
 	})
 
 	t.Run("dont skip", func(t *testing.T) {
@@ -195,6 +256,7 @@ func TestSkip(t *testing.T) {
 			},
 		}, withGoReleaserModulePath)
 		require.False(t, ProxyPipe{}.Skip(ctx))
+		require.False(t, CheckGoModPipe{}.Skip(ctx))
 	})
 }
 

internal/pipeline/pipeline.go

@@ -70,6 +70,8 @@ var BuildPipeline = []Piper{
 	// run prebuild stuff
 	prebuild.Pipe{},
 	// proxy gomod if needed
+	gomod.CheckGoModPipe{},
+	// proxy gomod if needed
 	gomod.ProxyPipe{},
 	// writes the actual config (with defaults et al set) to dist
 	effectiveconfig.Pipe{},