1 files changed, 143 insertions, 0 deletions
diff --git a/gazelle/bzl/gazelle_test.go b/gazelle/bzl/gazelle_test.go
new file mode 100644
index 0000000..e4f59e8
--- /dev/null
+++ b/gazelle/bzl/gazelle_test.go
@@ -0,0 +1,143 @@
+package bzl
+
+/* Copyright 2020 The Bazel Authors. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/bazelbuild/bazel-gazelle/testtools"
+	"github.com/bazelbuild/rules_go/go/tools/bazel"
+)
+
+var gazellePath = findGazelle()
+
+const testDataPath = "gazelle/bzl/testdata/"
+
+// TestGazelleBinary runs a gazelle binary with starlib installed on each
+// directory in `testdata/*`. Please see `testdata/README.md` for more
+// information on each test.
+func TestGazelleBinary(t *testing.T) {
+	tests := map[string][]bazel.RunfileEntry{}
+
+	files, err := bazel.ListRunfiles()
+	if err != nil {
+		t.Fatalf("bazel.ListRunfiles() error: %v", err)
+	}
+	for _, f := range files {
+		if strings.HasPrefix(f.ShortPath, testDataPath) {
+			relativePath := strings.TrimPrefix(f.ShortPath, testDataPath)
+			parts := strings.SplitN(relativePath, "/", 2)
+			if len(parts) < 2 {
+				// This file is not a part of a testcase since it must be in a dir that
+				// is the test case and then have a path inside of that.
+				continue
+			}
+
+			tests[parts[0]] = append(tests[parts[0]], f)
+		}
+	}
+	if len(tests) == 0 {
+		t.Fatal("no tests found")
+	}
+
+	for testName, files := range tests {
+		testPath(t, testName, files)
+	}
+}
+
+func testPath(t *testing.T, name string, files []bazel.RunfileEntry) {
+	t.Run(name, func(t *testing.T) {
+		var inputs []testtools.FileSpec
+		var goldens []testtools.FileSpec
+
+		for _, f := range files {
+			path := f.Path
+			trim := testDataPath + name + "/"
+			shortPath := strings.TrimPrefix(f.ShortPath, trim)
+			info, err := os.Stat(path)
+			if err != nil {
+				t.Fatalf("os.Stat(%q) error: %v", path, err)
+			}
+
+			// Skip dirs.
+			if info.IsDir() {
+				continue
+			}
+
+			content, err := ioutil.ReadFile(path)
+			if err != nil {
+				t.Errorf("ioutil.ReadFile(%q) error: %v", path, err)
+			}
+
+			// Now trim the common prefix off.
+			if strings.HasSuffix(shortPath, ".in") {
+				inputs = append(inputs, testtools.FileSpec{
+					Path:    strings.TrimSuffix(shortPath, ".in"),
+					Content: string(content),
+				})
+			} else if strings.HasSuffix(shortPath, ".out") {
+				goldens = append(goldens, testtools.FileSpec{
+					Path:    strings.TrimSuffix(shortPath, ".out"),
+					Content: string(content),
+				})
+			} else {
+				inputs = append(inputs, testtools.FileSpec{
+					Path:    shortPath,
+					Content: string(content),
+				})
+				goldens = append(goldens, testtools.FileSpec{
+					Path:    shortPath,
+					Content: string(content),
+				})
+			}
+		}
+
+		dir, cleanup := testtools.CreateFiles(t, inputs)
+		defer cleanup()
+
+		cmd := exec.Command(gazellePath, "-build_file_name=BUILD")
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		cmd.Dir = dir
+		if err := cmd.Run(); err != nil {
+			t.Fatal(err)
+		}
+
+		testtools.CheckFiles(t, dir, goldens)
+		if t.Failed() {
+			filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+				if err != nil {
+					return err
+				}
+				t.Logf("%q exists", path)
+				return nil
+			})
+		}
+	})
+}
+
+func findGazelle() string {
+	gazellePath, ok := bazel.FindBinary("gazelle/bzl", "gazelle-skylib")
+	if !ok {
+		panic("could not find gazelle binary")
+	}
+	return gazellePath
+}