Enhance LocalModule when no go sources found in project root

Signed-off-by: Petr Korobeinikov <pkorobeinikov@gmail.com>

README.md

@@ -50,8 +50,8 @@ Since v0.9.0, GCI always puts C import block as the first.
 
 ### LocalModule
 
-Local module detection is done via listing packages from *the directory where
-`gci` is invoked* and reading the modules off these. This means:
+Local module detection is done via reading the module name from the `go.mod`
+file in *the directory where `gci` is invoked*. This means:
 
   - This mode works when `gci` is invoked from a module root (i.e. directory
     containing `go.mod`)

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/spf13/cobra v1.6.1
 	github.com/stretchr/testify v1.8.1
 	go.uber.org/zap v1.24.0
+	golang.org/x/mod v0.8.0
 	golang.org/x/sync v0.1.0
 	golang.org/x/tools v0.6.0
 	gopkg.in/yaml.v3 v3.0.1
@@ -19,6 +20,5 @@ require (
 	github.com/spf13/pflag v1.0.5 // indirect
 	go.uber.org/atomic v1.7.0 // indirect
 	go.uber.org/multierr v1.6.0 // indirect
-	golang.org/x/mod v0.8.0 // indirect
 	golang.org/x/sys v0.5.0 // indirect
 )

pkg/gci/gci_test.go

@@ -21,10 +21,6 @@ func init() {
 }
 
 func TestRun(t *testing.T) {
-	// if runtime.GOOS == "windows" {
-	// 	t.Skip("Skipping test on Windows")
-	// }
-
 	for i := range testCases {
 		t.Run(fmt.Sprintf("run case: %s", testCases[i].name), func(t *testing.T) {
 			config, err := config.ParseConfig(testCases[i].config)
@@ -56,35 +52,65 @@ func chdir(t *testing.T, dir string) {
 func readConfig(t *testing.T, configPath string) *config.Config {
 	rawConfig, err := os.ReadFile(configPath)
 	require.NoError(t, err)
-	config, err := config.ParseConfig(string(rawConfig))
+	cfg, err := config.ParseConfig(string(rawConfig))
 	require.NoError(t, err)
 
-	return config
+	return cfg
 }
 
 func TestRunWithLocalModule(t *testing.T) {
-	moduleDir := filepath.Join("testdata", "module")
-	// files with a corresponding '*.out.go' file containing the expected
-	// result of formatting
-	testedFiles := []string{
-		"main.go",
-		filepath.Join("internal", "foo", "lib.go"),
+	tests := []struct {
+		name      string
+		moduleDir string
+		// files with a corresponding '*.out.go' file containing the expected
+		// result of formatting
+		testedFiles []string
+	}{
+		{
+			name:      `default module test case`,
+			moduleDir: filepath.Join("testdata", "module"),
+			testedFiles: []string{
+				"main.go",
+				filepath.Join("internal", "foo", "lib.go"),
+			},
+		},
+		{
+			name:      `canonical module without go sources in root dir`,
+			moduleDir: filepath.Join("testdata", "module_canonical"),
+			testedFiles: []string{
+				filepath.Join("cmd", "client", "main.go"),
+				filepath.Join("cmd", "server", "main.go"),
+				filepath.Join("internal", "foo", "lib.go"),
+			},
+		},
+		{
+			name:      `non-canonical module without go sources in root dir`,
+			moduleDir: filepath.Join("testdata", "module_noncanonical"),
+			testedFiles: []string{
+				filepath.Join("cmd", "client", "main.go"),
+				filepath.Join("cmd", "server", "main.go"),
+				filepath.Join("internal", "foo", "lib.go"),
+			},
+		},
 	}
-
-	// run subtests for expected module loading behaviour
-	chdir(t, moduleDir)
-	cfg := readConfig(t, "config.yaml")
-
-	for _, path := range testedFiles {
-		t.Run(path, func(t *testing.T) {
-			// *.go -> *.out.go
-			expected, err := os.ReadFile(strings.TrimSuffix(path, ".go") + ".out.go")
-			require.NoError(t, err)
-
-			_, got, err := LoadFormatGoFile(io.File{path}, *cfg)
-
-			require.NoError(t, err)
-			require.Equal(t, string(expected), string(got))
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// run subtests for expected module loading behaviour
+			chdir(t, tt.moduleDir)
+			cfg := readConfig(t, "config.yaml")
+
+			for _, path := range tt.testedFiles {
+				t.Run(path, func(t *testing.T) {
+					// *.go -> *.out.go
+					expected, err := os.ReadFile(strings.TrimSuffix(path, ".go") + ".out.go")
+					require.NoError(t, err)
+
+					_, got, err := LoadFormatGoFile(io.File{path}, *cfg)
+
+					require.NoError(t, err)
+					require.Equal(t, string(expected), string(got))
+				})
+			}
 		})
 	}
 }
@@ -96,18 +122,5 @@ func TestRunWithLocalModuleWithPackageLoadFailure(t *testing.T) {
 
 	chdir(t, dir)
 	_, err := config.ParseConfig(configContent)
-	require.ErrorContains(t, err, "failed to load local modules: ")
-}
-
-func TestRunWithLocalModuleWithModuleLookupError(t *testing.T) {
-	dir := t.TempDir()
-	// error from trying to list packages under module with no go files
-	configContent := "sections:\n  - LocalModule\n"
-	goModContent := "module example.com/foo\n"
-	require.NoError(t, os.WriteFile(filepath.Join(dir, "go.mod"), []byte(goModContent), 0o644))
-
-	chdir(t, dir)
-	_, err := config.ParseConfig(configContent)
-	require.ErrorContains(t, err, "error reading local packages: ")
-	require.ErrorContains(t, err, dir)
+	require.ErrorContains(t, err, "go.mod: open go.mod:")
 }

pkg/gci/testdata.go

@@ -1293,29 +1293,6 @@ import (
 	"fmt"
 	"net"
 )
-`,
-	},
-	{
-		"basic module",
-		// implicitly relies on the local module name being: github.com/daixiang0/gci
-		`sections:
-  - Standard
-  - LocalModule
-`,
-		`package main
-
-import (
-	"os"
-	"github.com/daixiang0/gci/cmd/gci"
-)
-`,
-		`package main
-
-import (
-	"os"
-
-	"github.com/daixiang0/gci/cmd/gci"
-)
 `,
 	},
 }

pkg/gci/testdata/module_canonical/.gitattributes

@@ -0,0 +1,4 @@
+# try and stop git running on Windows from converting line endings from
+# in all Go files under this directory. This is to avoid inconsistent test
+# results when `gci` strips "\r" characters
+**/*.go eol=lf

pkg/gci/testdata/module_canonical/cmd/client/main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"example.com/service/internal"
+	"example.com/service/internal/bar"
+	"example.com/service/internal/foo"
+	"golang.org/x/net"
+	"log"
+)

pkg/gci/testdata/module_canonical/cmd/client/main.out.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"log"
+
+	"golang.org/x/net"
+
+	"example.com/service/internal"
+	"example.com/service/internal/bar"
+	"example.com/service/internal/foo"
+)

pkg/gci/testdata/module_canonical/cmd/server/main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"example.com/service/internal"
+	"example.com/service/internal/bar"
+	"example.com/service/internal/foo"
+	"golang.org/x/net"
+	"log"
+)

pkg/gci/testdata/module_canonical/cmd/server/main.out.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"log"
+
+	"golang.org/x/net"
+
+	"example.com/service/internal"
+	"example.com/service/internal/bar"
+	"example.com/service/internal/foo"
+)

pkg/gci/testdata/module_canonical/config.yaml

@@ -0,0 +1,4 @@
+sections:
+  - Standard
+  - Default
+  - LocalModule

pkg/gci/testdata/module_canonical/go.mod

@@ -0,0 +1,3 @@
+module example.com/service
+
+go 1.20

pkg/gci/testdata/module_canonical/internal/bar/lib.go

@@ -0,0 +1 @@
+package bar

pkg/gci/testdata/module_canonical/internal/foo/lib.go

@@ -0,0 +1,6 @@
+package foo
+
+import (
+	"example.com/service/internal/bar"
+	"log"
+)

pkg/gci/testdata/module_canonical/internal/foo/lib.out.go

@@ -0,0 +1,7 @@
+package foo
+
+import (
+	"log"
+
+	"example.com/service/internal/bar"
+)

pkg/gci/testdata/module_canonical/internal/lib.go

@@ -0,0 +1 @@
+package internal

pkg/gci/testdata/module_noncanonical/.gitattributes

@@ -0,0 +1,4 @@
+# try and stop git running on Windows from converting line endings from
+# in all Go files under this directory. This is to avoid inconsistent test
+# results when `gci` strips "\r" characters
+**/*.go eol=lf

pkg/gci/testdata/module_noncanonical/cmd/client/main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"golang.org/x/net"
+	"log"
+	"service/internal"
+	"service/internal/bar"
+	"service/internal/foo"
+)

pkg/gci/testdata/module_noncanonical/cmd/client/main.out.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"log"
+
+	"golang.org/x/net"
+
+	"service/internal"
+	"service/internal/bar"
+	"service/internal/foo"
+)

pkg/gci/testdata/module_noncanonical/cmd/server/main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"golang.org/x/net"
+	"log"
+	"service/internal"
+	"service/internal/bar"
+	"service/internal/foo"
+)

pkg/gci/testdata/module_noncanonical/cmd/server/main.out.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"log"
+
+	"golang.org/x/net"
+
+	"service/internal"
+	"service/internal/bar"
+	"service/internal/foo"
+)

pkg/gci/testdata/module_noncanonical/config.yaml

@@ -0,0 +1,4 @@
+sections:
+  - Standard
+  - Default
+  - LocalModule

pkg/gci/testdata/module_noncanonical/go.mod

@@ -0,0 +1,3 @@
+module service
+
+go 1.20

pkg/gci/testdata/module_noncanonical/internal/bar/lib.go

@@ -0,0 +1 @@
+package bar

pkg/gci/testdata/module_noncanonical/internal/foo/lib.go

@@ -0,0 +1,6 @@
+package foo
+
+import (
+	"log"
+	"service/internal/bar"
+)

pkg/gci/testdata/module_noncanonical/internal/foo/lib.out.go

@@ -0,0 +1,7 @@
+package foo
+
+import (
+	"log"
+
+	"service/internal/bar"
+)

pkg/gci/testdata/module_noncanonical/internal/lib.go

@@ -0,0 +1 @@
+package internal