Skip .git folders in file listings

The file listing mechanism will traverse all directories given to it & return a listing of all files. The main purpose of this mechanism is to detect changes under a directory structure. This change will skip `.git` folders as the file listing is traversing subdirectories. This is because `.git` folders are well-know, can change independent of the application (like if you change git config) but shouldn't trigger rebuilds of the application. In additiona, the `.git` directory can for larger projects contain a large number of files, so skipping it can help with performance on large projects.

This change will skip all folders with the name `.git`, not just the top-level `.git` folder.

This resolves #55.

Signed-off-by: Daniel Mikusa <dmikusa@vmware.com>

sherpa/file_listing.go

@@ -84,6 +84,10 @@ func NewFileListing(roots ...string) ([]FileEntry, error) {
 					return nil
 				}
 
+				if info.IsDir() && info.Name() == ".git" {
+					return filepath.SkipDir
+				}
+
 				e := FileEntry{
 					Path: path,
 					Mode: info.Mode().String(),

sherpa/file_listing_test.go

@@ -59,6 +59,22 @@ func testFileListing(t *testing.T, context spec.G, it spec.S) {
 		Expect(e).To(HaveLen(3))
 	})
 
+	it("create listing skipping .git folder", func() {
+		Expect(os.MkdirAll(filepath.Join(path, ".git"), 0755)).To(Succeed())
+		Expect(ioutil.WriteFile(filepath.Join(path, ".git", "HEAD"), []byte{1}, 0644)).To(Succeed())
+		Expect(ioutil.WriteFile(filepath.Join(path, ".git", "config"), []byte{1}, 0644)).To(Succeed())
+		Expect(ioutil.WriteFile(filepath.Join(path, "alpha.txt"), []byte{1}, 0644)).To(Succeed())
+		Expect(os.MkdirAll(filepath.Join(path, "test-directory"), 0755)).To(Succeed())
+		Expect(ioutil.WriteFile(filepath.Join(path, "test-directory", "bravo.txt"), []byte{2}, 0644)).To(Succeed())
+		Expect(os.MkdirAll(filepath.Join(path, "test-directory", ".git"), 0755)).To(Succeed())
+		Expect(ioutil.WriteFile(filepath.Join(path, "test-directory", ".git", "config"), []byte{1}, 0644)).To(Succeed())
+
+		e, err := sherpa.NewFileListing(path)
+		Expect(err).NotTo(HaveOccurred())
+
+		Expect(e).To(HaveLen(3))
+	})
+
 	it("create listing as hash with non-regular file", func() {
 		Expect(ioutil.WriteFile(filepath.Join(path, "alpha.txt"), []byte{1}, 0644)).To(Succeed())
 		Expect(os.MkdirAll(filepath.Join(path, "test-directory"), 0755)).To(Succeed())