WIP: refactor E2E test

Author: blewis12

tools/generate-module-dependencies/e2e_test.go

@@ -68,89 +68,66 @@ type testEnv struct {
 	goModPath string
 }
 
-// setupTestEnv sets up the test environment with all necessary files and directories.
+// setupTestEnvFromTestdata sets up the test environment by copying testdata and tool source.
 // It returns a testEnv struct with all the paths needed for the test.
-func setupTestEnv(t *testing.T, yamlContent, goModContent string) *testEnv {
+func setupTestEnvFromTestdata(t *testing.T, testdataDir string) *testEnv {
 	t.Helper()
 
-	tmpDir := t.TempDir()
-	scriptDir := filepath.Join(tmpDir, "tools", "generate-module-dependencies")
-	if err := os.MkdirAll(scriptDir, 0755); err != nil {
-		t.Fatalf("Failed to create script directory: %v", err)
-	}
-
-	projectRoot := tmpDir
-
-	// Create dependency-replacements.yaml
-	yamlPath := filepath.Join(projectRoot, "dependency-replacements.yaml")
-	if err := os.WriteFile(yamlPath, []byte(yamlContent), 0644); err != nil {
-		t.Fatalf("Failed to write dependency-replacements.yaml: %v", err)
-	}
-
-	// Create replaces-mod.tpl template
-	templateContent := `// BEGIN GENERATED REPLACES - DO NOT EDIT
-// Generated by go generate - DO NOT EDIT MANUALLY
-{{- range . }}
-{{- if .Comment }}
-// {{ .Comment }}
-{{- end }}
-replace {{ .Dependency }} => {{ .Replacement }}
-{{ end -}}
-// END GENERATED REPLACES
-
-`
-	templatePath := filepath.Join(scriptDir, "replaces-mod.tpl")
-	if err := os.WriteFile(templatePath, []byte(templateContent), 0644); err != nil {
-		t.Fatalf("Failed to write replaces-mod.tpl: %v", err)
-	}
-
-	// Create go.mod file (this is the target file we'll modify)
-	goModPath := filepath.Join(projectRoot, "go.mod")
-	if err := os.WriteFile(goModPath, []byte(goModContent), 0644); err != nil {
-		t.Fatalf("Failed to write go.mod: %v", err)
-	}
-
-	// Get the original working directory before changing
 	originalWd, err := os.Getwd()
 	if err != nil {
 		t.Fatalf("Failed to get current working directory: %v", err)
 	}
 
-	// Copy go.mod and go.sum to the test script directory so go generate can resolve dependencies
-	originalGoMod := filepath.Join(originalWd, "go.mod")
-	originalGoSum := filepath.Join(originalWd, "go.sum")
+	// Get the testdata directory path
+	testdataPath := filepath.Join(originalWd, "testdata", testdataDir)
+	if _, err := os.Stat(testdataPath); os.IsNotExist(err) {
+		t.Fatalf("Testdata directory not found: %s", testdataPath)
+	}
 
-	testGoMod := filepath.Join(scriptDir, "go.mod")
-	testGoSum := filepath.Join(scriptDir, "go.sum")
+	tmpDir := t.TempDir()
+	projectRoot := tmpDir
+	scriptDir := filepath.Join(tmpDir, "tools", "generate-module-dependencies")
 
-	// Copy go.mod and go.sum
-	goModData, err := os.ReadFile(originalGoMod)
-	if err != nil {
-		t.Fatalf("Failed to read original go.mod: %v", err)
-	}
-	if err := os.WriteFile(testGoMod, goModData, 0644); err != nil {
-		t.Fatalf("Failed to copy go.mod to test directory: %v", err)
+	// Copy testdata files to project root
+	testdataYaml := filepath.Join(testdataPath, "dependency-replacements.yaml")
+	projectYaml := filepath.Join(projectRoot, "dependency-replacements.yaml")
+	if err := copyFile(testdataYaml, projectYaml); err != nil {
+		t.Fatalf("Failed to copy dependency-replacements.yaml: %v", err)
 	}
 
-	if goSumData, err := os.ReadFile(originalGoSum); err == nil {
-		if err := os.WriteFile(testGoSum, goSumData, 0644); err != nil {
-			t.Fatalf("Failed to copy go.sum to test directory: %v", err)
-		}
+	testdataGoMod := filepath.Join(testdataPath, "go.mod")
+	goModPath := filepath.Join(projectRoot, "go.mod")
+	if err := copyFile(testdataGoMod, goModPath); err != nil {
+		t.Fatalf("Failed to copy go.mod: %v", err)
 	}
 
-	// Copy the internal directory structure so imports can be resolved
-	originalInternal := filepath.Join(originalWd, "internal")
-	testInternal := filepath.Join(scriptDir, "internal")
+	// Copy tool source code to script directory
+	if err := os.MkdirAll(scriptDir, 0755); err != nil {
+		t.Fatalf("Failed to create script directory: %v", err)
+	}
 
-	if err := copyDir(originalInternal, testInternal); err != nil {
-		t.Fatalf("Failed to copy internal directory: %v", err)
+	// Copy all necessary tool files
+	toolFiles := []string{"replaces-mod.tpl", "main.go", "generate.go", "go.mod", "go.sum"}
+	for _, file := range toolFiles {
+		src := filepath.Join(originalWd, file)
+		dst := filepath.Join(scriptDir, file)
+		if _, err := os.Stat(src); err == nil {
+			if err := copyFile(src, dst); err != nil {
+				t.Fatalf("Failed to copy %s: %v", file, err)
+			}
+		}
 	}
 
-	// Copy generate.go
-	originalGenerateGo := filepath.Join(originalWd, "generate.go")
-	testGenerateGo := filepath.Join(scriptDir, "generate.go")
-	if err := copyFile(originalGenerateGo, testGenerateGo); err != nil {
-		t.Fatalf("Failed to copy generate.go: %v", err)
+	// Copy tool directories
+	toolDirs := []string{"internal", "cmd"}
+	for _, dir := range toolDirs {
+		src := filepath.Join(originalWd, dir)
+		dst := filepath.Join(scriptDir, dir)
+		if _, err := os.Stat(src); err == nil {
+			if err := copyDir(src, dst); err != nil {
+				t.Fatalf("Failed to copy %s directory: %v", dir, err)
+			}
+		}
 	}
 
 	return &testEnv{
@@ -159,8 +136,8 @@ replace {{ .Dependency }} => {{ .Replacement }}
 	}
 }
 
-// runGoGenerate runs `go generate` in the test environment
-func runGoGenerate(t *testing.T, env *testEnv) {
+// runCommand runs the generate command in the test environment
+func runCommand(t *testing.T, env *testEnv) {
 	t.Helper()
 
 	// Change to script directory to simulate running from there
@@ -174,59 +151,67 @@ func runGoGenerate(t *testing.T, env *testEnv) {
 		t.Fatalf("Failed to change to script directory: %v", err)
 	}
 
-	// Run go generate
-	cmd := exec.Command("go", "generate")
+	// Calculate the project root relative to scriptDir
+	// scriptDir is tmpDir/tools/generate-module-dependencies
+	// project root should be tmpDir (two levels up)
+	projectRoot := filepath.Join(env.scriptDir, "..", "..")
+	projectRoot, err = filepath.Abs(projectRoot)
+	if err != nil {
+		t.Fatalf("Failed to resolve project root: %v", err)
+	}
+
+	// Calculate the yaml path relative to scriptDir
+	// dependency-replacements.yaml is at projectRoot/dependency-replacements.yaml
+	yamlPath := filepath.Join(projectRoot, "dependency-replacements.yaml")
+	relYamlPath, err := filepath.Rel(env.scriptDir, yamlPath)
+	if err != nil {
+		t.Fatalf("Failed to calculate relative yaml path: %v", err)
+	}
+
+	// Calculate relative project root path
+	relProjectRoot, err := filepath.Rel(env.scriptDir, projectRoot)
+	if err != nil {
+		t.Fatalf("Failed to calculate relative project root: %v", err)
+	}
+
+	// Run the command directly
+	cmd := exec.Command("go", "run", "main.go", "generate",
+		"--dependency-yaml", relYamlPath,
+		"--project-root", relProjectRoot)
 	cmd.Dir = env.scriptDir
 	output, err := cmd.CombinedOutput()
 	if err != nil {
-		t.Logf("go generate output: %s", string(output))
-		t.Fatalf("Failed to run go generate: %v", err)
+		t.Logf("Command output: %s", string(output))
+		t.Fatalf("Failed to run command: %v", err)
 	}
 }
 
 // ##################################################################################
 // ################################### E2E TESTS ####################################
 // ##################################################################################
 
-// TestE2E tests the full pipeline: generating replaces from YAML and applying them to go.mod
-func TestE2E(t *testing.T) {
+// TestE2E_Basic tests the full pipeline: generating replaces from YAML and applying them to go.mod
+// This test uses the testdata/basic directory which contains a simple example project.
+func TestE2E_Basic(t *testing.T) {
 	originalWd, err := os.Getwd()
 	if err != nil {
 		t.Fatalf("Failed to get current working directory: %v", err)
 	}
 	defer os.Chdir(originalWd)
 
-	// Test-specific setup: YAML and go.mod content
-	yamlContent := `modules:
-  - name: test-module
-    path: go.mod
-    file_type: mod
-
-replaces:
-  - comment: Test replace for example.com/package
-    dependency: example.com/package
-    replacement: example.com/fork v1.0.0
-
-  - comment: Another test replace
-    dependency: github.com/test/dependency
-    replacement: github.com/test/fork v1.0.0
-`
-
-	goModContent := `module test.example.com
+	// Set up test environment from testdata
+	env := setupTestEnvFromTestdata(t, "basic")
 
-go 1.21
+	// Run the generate command
+	runCommand(t, env)
 
-require (
-	example.com/package v0.1.0
-	github.com/test/dependency v1.0.0
-)
-`
-
-	// Set up test environment
-	env := setupTestEnv(t, yamlContent, goModContent)
-
-	// Run go generate
-	runGoGenerate(t, env)
+	// Read expected output from testdata
+	expectedPath := filepath.Join("testdata", "basic", "go.mod.expected")
+	expectedContent, err := os.ReadFile(expectedPath)
+	if err != nil {
+		t.Fatalf("Failed to read expected go.mod: %v", err)
+	}
+	expectedGoMod := strings.TrimSpace(string(expectedContent))
 
 	// Verify go.mod was updated
 	updatedGoModContent, err := os.ReadFile(env.goModPath)
@@ -236,69 +221,34 @@ require (
 
 	actualGoMod := strings.TrimSpace(string(updatedGoModContent))
 
-	// Define expected go.mod content
-	// Note: go mod tidy removes unused dependencies, so the require block is removed
-	expectedGoMod := `module test.example.com
-
-go 1.21
-
-// BEGIN GENERATED REPLACES - DO NOT EDIT
-// Generated by go generate - DO NOT EDIT MANUALLY
-// Test replace for example.com/package
-replace example.com/package => example.com/fork v1.0.0
-
-// Another test replace
-replace github.com/test/dependency => github.com/test/fork v1.0.0
-
-// END GENERATED REPLACES`
-
-	expectedGoMod = strings.TrimSpace(expectedGoMod)
-
 	if actualGoMod != expectedGoMod {
 		t.Errorf("go.mod content mismatch.\nExpected:\n%s\n\nActual:\n%s", expectedGoMod, actualGoMod)
 	}
 }
 
-// TestE2E_UpdateExisting tests updating an existing generated block
+// TestE2E_UpdateExisting tests updating an existing generated block.
+// This test uses the testdata/update-existing directory which contains a go.mod
+// with an existing generated block that should be updated.
 func TestE2E_UpdateExisting(t *testing.T) {
 	originalWd, err := os.Getwd()
 	if err != nil {
 		t.Fatalf("Failed to get current working directory: %v", err)
 	}
 	defer os.Chdir(originalWd)
 
-	// Test-specific setup: YAML and go.mod content with existing generated block
-	yamlContent := `modules:
-  - name: test-module
-    path: go.mod
-    file_type: mod
-
-replaces:
-  - comment: Updated replace
-    dependency: example.com/package
-    replacement: example.com/fork v1.1.0
-`
-
-	goModContent := `module test.example.com
-
-go 1.21
-
-require (
-	example.com/package v0.1.0
-)
-
-// BEGIN GENERATED REPLACES - DO NOT EDIT
-// Generated by go generate - DO NOT EDIT MANUALLY
-// Old comment
-replace example.com/package => example.com/fork v1.0.0
-// END GENERATED REPLACES
-`
+	// Set up test environment from testdata
+	env := setupTestEnvFromTestdata(t, "update-existing")
 
-	// Set up test environment
-	env := setupTestEnv(t, yamlContent, goModContent)
+	// Run the generate command
+	runCommand(t, env)
 
-	// Run go generate
-	runGoGenerate(t, env)
+	// Read expected output from testdata
+	expectedPath := filepath.Join("testdata", "update-existing", "go.mod.expected")
+	expectedContent, err := os.ReadFile(expectedPath)
+	if err != nil {
+		t.Fatalf("Failed to read expected go.mod: %v", err)
+	}
+	expectedGoMod := strings.TrimSpace(string(expectedContent))
 
 	// Verify go.mod was updated
 	updatedGoModContent, err := os.ReadFile(env.goModPath)
@@ -308,22 +258,6 @@ replace example.com/package => example.com/fork v1.0.0
 
 	actualGoMod := strings.TrimSpace(string(updatedGoModContent))
 
-	// Define expected go.mod content
-	// Note: go mod tidy removes unused dependencies, so the require block is removed
-	// The old replace should be replaced with the new one
-	expectedGoMod := `module test.example.com
-
-go 1.21
-
-// BEGIN GENERATED REPLACES - DO NOT EDIT
-// Generated by go generate - DO NOT EDIT MANUALLY
-// Updated replace
-replace example.com/package => example.com/fork v1.1.0
-
-// END GENERATED REPLACES`
-
-	expectedGoMod = strings.TrimSpace(expectedGoMod)
-
 	if actualGoMod != expectedGoMod {
 		t.Errorf("go.mod content mismatch.\nExpected:\n%s\n\nActual:\n%s", expectedGoMod, actualGoMod)
 	}

tools/generate-module-dependencies/testdata/basic/dependency-replacements.yaml

@@ -0,0 +1,14 @@
+modules:
+  - name: test-module
+    path: go.mod
+    file_type: mod
+
+replaces:
+  - comment: Test replace for example.com/package
+    dependency: example.com/package
+    replacement: example.com/fork v1.0.0
+
+  - comment: Another test replace
+    dependency: github.com/test/dependency
+    replacement: github.com/test/fork v1.0.0
+

tools/generate-module-dependencies/testdata/basic/go.mod

@@ -0,0 +1,9 @@
+module test.example.com
+
+go 1.21
+
+require (
+	example.com/package v0.1.0
+	github.com/test/dependency v1.0.0
+)
+

tools/generate-module-dependencies/testdata/basic/go.mod.expected

@@ -0,0 +1,14 @@
+module test.example.com
+
+go 1.21
+
+// BEGIN GENERATED REPLACES - DO NOT EDIT
+// Generated by go generate - DO NOT EDIT MANUALLY
+// Test replace for example.com/package
+replace example.com/package => example.com/fork v1.0.0
+
+// Another test replace
+replace github.com/test/dependency => github.com/test/fork v1.0.0
+
+// END GENERATED REPLACES
+