feat(runtime/go): smart ShouldRebuild via go list -deps

pkg/runtime/golang/build_test.go

@@ -0,0 +1,211 @@
+package golang
+
+import (
+	"context"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// testIntegrationEnv returns a minimal, hermetic env for `go list`.
+// GOTOOLCHAIN=local prevents network downloads of mismatched
+// toolchains, GOPROXY=off prevents module fetches, GOMODCACHE/GOCACHE
+// are redirected so the host caches stay untouched. GOWORK=off keeps
+// the test isolated from any go.work file the host may have.
+func testIntegrationEnv(t *testing.T) []string {
+	t.Helper()
+	return []string{
+		"PATH=" + os.Getenv("PATH"),
+		"HOME=" + t.TempDir(),
+		"GOMODCACHE=" + filepath.Join(t.TempDir(), "modcache"),
+		"GOCACHE=" + filepath.Join(t.TempDir(), "gocache"),
+		"GOPROXY=off",
+		"GOFLAGS=-mod=mod",
+		"GOTOOLCHAIN=local",
+		"GOWORK=off",
+		"GOSUMDB=off",
+	}
+}
+
+// requireGoToolchain skips when `go test -short` is set or when the
+// `go` binary is not in PATH.
+func requireGoToolchain(t *testing.T) {
+	t.Helper()
+	if testing.Short() {
+		t.Skip("integration test; skipped under -short")
+	}
+	if _, err := exec.LookPath("go"); err != nil {
+		t.Skipf("go toolchain not available: %v", err)
+	}
+}
+
+func TestCaptureDeps_SimpleMain(t *testing.T) {
+	requireGoToolchain(t)
+
+	dir := t.TempDir()
+	mustWriteFile(t, filepath.Join(dir, "go.mod"), "module example.test\n\ngo 1.22\n")
+	main := filepath.Join(dir, "main.go")
+	mustWriteFile(t, main, "package main\n\nfunc main() {}\n")
+
+	r := New()
+	deps, err := r.captureDeps(context.Background(), dir, ".", testIntegrationEnv(t))
+	if err != nil {
+		t.Fatalf("captureDeps: %v", err)
+	}
+	files := deps.files
+
+	if _, ok := files[main]; !ok {
+		t.Errorf("expected main.go (%s) in captured files, got %v", main, keys(files))
+	}
+	for f := range files {
+		if !strings.HasPrefix(f, dir) {
+			t.Errorf("captured file outside module root: %s (root=%s)", f, dir)
+		}
+	}
+}
+
+func TestCaptureDeps_LocalDependency(t *testing.T) {
+	requireGoToolchain(t)
+
+	dir := t.TempDir()
+	mustWriteFile(t, filepath.Join(dir, "go.mod"), "module example.test\n\ngo 1.22\n")
+
+	mustMkdirAll(t, filepath.Join(dir, "shared"))
+	sharedFile := filepath.Join(dir, "shared", "lib.go")
+	mustWriteFile(t, sharedFile, "package shared\n\nfunc Hello() string { return \"hi\" }\n")
+
+	mainFile := filepath.Join(dir, "main.go")
+	mustWriteFile(t, mainFile,
+		"package main\n\nimport \"example.test/shared\"\n\nfunc main() { _ = shared.Hello() }\n")
+
+	r := New()
+	deps, err := r.captureDeps(context.Background(), dir, ".", testIntegrationEnv(t))
+	if err != nil {
+		t.Fatalf("captureDeps: %v", err)
+	}
+	files := deps.files
+
+	if _, ok := files[mainFile]; !ok {
+		t.Errorf("expected main.go (%s) in captured files, got %v", mainFile, keys(files))
+	}
+	if _, ok := files[sharedFile]; !ok {
+		t.Errorf("expected shared/lib.go (%s) in captured files, got %v", sharedFile, keys(files))
+	}
+}
+
+func TestCaptureDeps_NoFilesOutsideModuleRoot(t *testing.T) {
+	requireGoToolchain(t)
+
+	dir := t.TempDir()
+	mustWriteFile(t, filepath.Join(dir, "go.mod"), "module example.test\n\ngo 1.22\n")
+	mustWriteFile(t, filepath.Join(dir, "main.go"),
+		"package main\n\nimport \"fmt\"\n\nfunc main() { fmt.Println(\"hi\") }\n")
+
+	r := New()
+	deps, err := r.captureDeps(context.Background(), dir, ".", testIntegrationEnv(t))
+	if err != nil {
+		t.Fatalf("captureDeps: %v", err)
+	}
+	files := deps.files
+
+	for f := range files {
+		if !strings.HasPrefix(f, dir) {
+			t.Errorf("file outside module root leaked into captured set: %s", f)
+		}
+	}
+}
+
+func TestCaptureDeps_NoTestFilesIncluded(t *testing.T) {
+	requireGoToolchain(t)
+
+	dir := t.TempDir()
+	mustWriteFile(t, filepath.Join(dir, "go.mod"), "module example.test\n\ngo 1.22\n")
+	mustWriteFile(t, filepath.Join(dir, "main.go"), "package main\n\nfunc main() {}\n")
+	testFile := filepath.Join(dir, "main_test.go")
+	mustWriteFile(t, testFile, "package main\n\nimport \"testing\"\n\nfunc TestX(t *testing.T) {}\n")
+
+	r := New()
+	deps, err := r.captureDeps(context.Background(), dir, ".", testIntegrationEnv(t))
+	if err != nil {
+		t.Fatalf("captureDeps: %v", err)
+	}
+	files := deps.files
+
+	if _, ok := files[testFile]; ok {
+		t.Errorf("test file %s leaked into captured set", testFile)
+	}
+}
+
+func TestCaptureDeps_BrokenSourceFails(t *testing.T) {
+	requireGoToolchain(t)
+
+	dir := t.TempDir()
+	mustWriteFile(t, filepath.Join(dir, "go.mod"), "module example.test\n\ngo 1.22\n")
+	mustWriteFile(t, filepath.Join(dir, "main.go"), "this is not valid go source")
+
+	r := New()
+	if _, err := r.captureDeps(context.Background(), dir, ".", testIntegrationEnv(t)); err == nil {
+		t.Error("expected error on unparseable source, got nil")
+	}
+}
+
+func TestCaptureDeps_SubPackageHandler(t *testing.T) {
+	requireGoToolchain(t)
+
+	dir := t.TempDir()
+	mustWriteFile(t, filepath.Join(dir, "go.mod"), "module example.test\n\ngo 1.22\n")
+
+	mustMkdirAll(t, filepath.Join(dir, "shared"))
+	sharedFile := filepath.Join(dir, "shared", "lib.go")
+	mustWriteFile(t, sharedFile, "package shared\n\nfunc Hello() string { return \"hi\" }\n")
+
+	mustMkdirAll(t, filepath.Join(dir, "lambdas", "alpha"))
+	alphaFile := filepath.Join(dir, "lambdas", "alpha", "main.go")
+	mustWriteFile(t, alphaFile,
+		"package main\n\nimport \"example.test/shared\"\n\nfunc main() { _ = shared.Hello() }\n")
+
+	mustMkdirAll(t, filepath.Join(dir, "lambdas", "beta"))
+	betaFile := filepath.Join(dir, "lambdas", "beta", "main.go")
+	mustWriteFile(t, betaFile, "package main\n\nfunc main() {}\n")
+
+	r := New()
+	deps, err := r.captureDeps(context.Background(), dir, "lambdas/alpha", testIntegrationEnv(t))
+	if err != nil {
+		t.Fatalf("captureDeps: %v", err)
+	}
+	files := deps.files
+
+	if _, ok := files[alphaFile]; !ok {
+		t.Errorf("expected alpha main.go in captured files, got %v", keys(files))
+	}
+	if _, ok := files[sharedFile]; !ok {
+		t.Errorf("expected shared/lib.go in captured files, got %v", keys(files))
+	}
+	if _, ok := files[betaFile]; ok {
+		t.Errorf("beta sibling main.go must NOT be in alpha's import graph: %s", betaFile)
+	}
+}
+
+func keys(m map[string]struct{}) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	return out
+}
+
+func mustMkdirAll(t *testing.T, dir string) {
+	t.Helper()
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func mustWriteFile(t *testing.T, path string, contents string) {
+	t.Helper()
+	if err := os.WriteFile(path, []byte(contents), 0o644); err != nil {
+		t.Fatal(err)
+	}
+}