From 1031af3dbc0fc75eacd7e7adb077cb39bd943d2c Mon Sep 17 00:00:00 2001
From: Mat Scales <mat@netcopy.co.uk>
Date: Tue, 30 Apr 2013 11:23:28 +0100
Subject: [PATCH] Allow a commit hash instead of a semver version (#275)

---
 lib/core/package.js | 60 +++++++++++++++++++++++++++++++--------------
 test/package.js     | 42 +++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+), 19 deletions(-)

diff --git a/lib/core/package.js b/lib/core/package.js
index 05f04fc3..2ae9b9ca 100755
--- a/lib/core/package.js
+++ b/lib/core/package.js
@@ -666,6 +666,34 @@ Package.prototype.checkout = function () {
   template('action', { name: 'fetching', shizzle: this.name })
     .on('data', this.emit.bind(this, 'data'));
 
+  var doCheckout = function () {
+    template('action', {
+      name: 'checking out',
+      shizzle: this.name + '#' + this.tag
+    }).on('data', this.emit.bind(this, 'data'));
+
+    // Checkout the tag
+    git([ 'checkout', this.tag, '-f'], { cwd: this.path }, this).on('close', function (code) {
+      if (code) return;
+      // Ensure that checkout the tag as it is, removing all untracked files
+      git(['clean', '-f', '-d'], { cwd: this.path }, this).on('close', function (code) {
+        if (code) return;
+        this.emit('checkout');
+        this.loadJSON();
+      }.bind(this));
+    }.bind(this));
+  }.bind(this);
+
+  if (this.tag && !semver.validRange(this.tag)) {
+    // We might have a commit. Check that this is a valid commit SHA
+    return this.validCommit(this.tag, function (isValid) {
+      if (!isValid) {
+        return this.emit('error', new Error('Tag ' + this.tag + ' is not a valid semver range/version or a valid commit hash'));
+      }
+      doCheckout();
+    }.bind(this));
+  }
+
   this.once('versions', function (versions) {
     if (!versions.length) {
       this.emit('checkout');
@@ -674,10 +702,6 @@ Package.prototype.checkout = function () {
 
     // If tag is specified, try to satisfy it
     if (this.tag) {
-      if (!semver.validRange(this.tag)) {
-        return this.emit('error', new Error('Tag ' + this.tag + ' is not a valid semver range/version'));
-      }
-
       versions = versions.filter(function (version) {
         return semver.satisfies(version, this.tag);
       }.bind(this));
@@ -694,25 +718,23 @@ Package.prototype.checkout = function () {
     if (!semver.valid(this.tag)) this.commit = this.tag;  // If the version is not valid, then its a commit
 
     if (this.tag) {
-      template('action', {
-        name: 'checking out',
-        shizzle: this.name + '#' + this.tag
-      }).on('data', this.emit.bind(this, 'data'));
-
-      // Checkout the tag
-      git([ 'checkout', this.tag, '-f'], { cwd: this.path }, this).on('close', function (code) {
-        if (code) return;
-        // Ensure that checkout the tag as it is, removing all untracked files
-        git(['clean', '-f', '-d'], { cwd: this.path }, this).on('close', function (code) {
-          if (code) return;
-          this.emit('checkout');
-          this.loadJSON();
-        }.bind(this));
-      }.bind(this));
+      doCheckout();
     }
   }).versions();
 };
 
+Package.prototype.validCommit = function (hash, callback) {
+  var emitter = new events.EventEmitter();
+  var cp = git(['branch', '-q', '--contains', hash], { cwd: this.gitPath }, emitter);
+  cp.on('close', function (code) {
+    if (code) callback(false);
+    callback(true);
+  });
+  emitter.on('error', function () {
+    callback(false);
+  });
+};
+
 Package.prototype.describeTag = function () {
   var cp = git(['describe', '--always', '--tag'], { cwd: this.gitPath || this.path, ignoreCodes: [128] }, this);
   var tag = '';
diff --git a/test/package.js b/test/package.js
index 3775574f..3e305887 100644
--- a/test/package.js
+++ b/test/package.js
@@ -682,4 +682,46 @@ describe('package', function () {
 
     pkg.resolve();
   });
+
+  it('Should give a meaningful error if the commit does not exist', function (next) {
+    var commit = '000002a7b4e31cad48886d67446eb31faad92683';
+    var pkg = new Package('jquery', 'git://github.com/maccman/package-jquery.git#' + commit);
+
+    pkg.on('resolve', function () {
+      pkg.install();
+    });
+
+    pkg.on('error', function (err) {
+      assert(/not a valid semver range\/version or a valid commit hash/.test(err.message));
+      next();
+    });
+
+    pkg.on('checkout', function () {
+      assert(false);
+      next();
+    });
+
+    pkg.resolve();
+  });
+
+  it('Should allow you to specify a git commit rather than a tag version', function (next) {
+    var commit = 'd54062a7b4e31cad48886d67446ea31faad92683';
+    var pkg = new Package('jquery', 'git://github.com/maccman/package-jquery.git#' + commit);
+
+    pkg.on('resolve', function () {
+      pkg.install();
+    });
+
+    pkg.on('error', function (err) {
+      throw err;
+    });
+
+    pkg.on('checkout', function () {
+      assert(fs.existsSync(pkg.gitPath));
+      assert.equal(fs.readFileSync(path.join(pkg.gitPath, '.git/HEAD'), 'UTF-8'), commit + '\n');
+      next();
+    });
+
+    pkg.resolve();
+  });
 });