Support Git submodules.

lib/utils.js

@@ -131,30 +131,60 @@ exports.isDir = function (path) {
 };
 
 
+// Given a path, determine if the path is a regular file
+exports.isFile = function (path) {
+
+    try {
+        var stat = Fs.statSync(path);
+        return stat.isFile();
+    }
+    catch (e) {
+        return false;
+    }
+};
+
+
 // Given a starting directory, find the root of a git repository.
-// In this case, the root is defined as the first directory that contains
-// a directory named ".git"
 //
-// Returns a string if found, otherwise undefined
+// Returns undefined if not found, otherwise an object containing:
+//   root: path to the root of the Git repo
+//     - this is the first directory (traversing upward) that contains a ".git"
+//       directory (most cases) or a ".git" file (submodule inside another Git repo)
+//   gitDir: path to the ".git"-ish directory of the Git repo
+//     - in most cases, this is the ".git" directory inside the Git repo root
+//     - in the submodule case, this is the directory pointed to by the ".git" file
 exports.findGitRoot = function (start) {
 
     start = start || Path.dirname(internals.findParent(module).filename);
     var root;
+    var gitDir = Path.join(start, '.git');
 
-    if (exports.isDir(Path.join(start, '.git'))) {
+    if (exports.isDir(gitDir)) {
+        root = start;
+    }
+    else if (exports.isFile(gitDir)) {
+        // This is a git submodule inside another git repo!
+        // Resolve the path to its ".git"-ish directory.
         root = start;
+        gitFile = Fs.readFileSync(gitDir, { encoding: 'utf8' });
+        matches = gitFile.split('\n')[0].match(/^gitdir: (.+)$/);
+        if (!matches) {
+            return internals.throwWarn('Unable to find a .git directory for this (submodule) project');
+        }
+        // This path is relative to the root of the Git repo.
+        gitDir = Path.join(root, matches[1]);
     }
     /* $lab:coverage:off$ */
     // Coverage disabled here due to false positive on else if, since we have to trap the throwWarn method
     else if (Path.dirname(start) !== start) {
-        root = exports.findGitRoot(Path.dirname(start));
+        return exports.findGitRoot(Path.dirname(start));
     }
     else {
         return internals.throwWarn('Unable to find a .git directory for this project');
     }
     /* $lab:coverage:on$ */
 
-    return root;
+    return { root: root, gitDir: gitDir };
 };
 
 
@@ -191,7 +221,10 @@ exports.findProjectRoot = function (start) {
 // Returns an array
 exports.findProjects = function (start, depth) {
 
-    start = start || exports.findGitRoot(internals.findParent(module).filename);
+    if (!start) {
+        gitRoot = exports.findGitRoot(internals.findParent(module).filename);
+        start = gitRoot ? gitRoot.root : undefined;
+    }
     depth = depth || 0;
     ++depth;
 
@@ -229,8 +262,8 @@ exports.findProjects = function (start, depth) {
 exports.installHooks = function (hooks, root) {
 
     hooks = Array.isArray(hooks) ? hooks : [hooks];
-    var gitRoot = exports.findGitRoot(root);
-    var hookRoot = Path.join(gitRoot, '.git', 'hooks');
+    var hookRoot = Path.join(exports.findGitRoot(root).gitDir, 'hooks');
+
     var source = Path.resolve(__dirname, '..', 'bin', 'validate.sh');
 
     if (!exports.isDir(hookRoot)) {