Added .getConfigValue

spec/git-repository-async-spec.js

@@ -472,9 +472,8 @@ describe('GitRepositoryAsync', () => {
   })
 
   describe('.getReferences(path)', () => {
-    let workingDirectory
     beforeEach(() => {
-      workingDirectory = copyRepository()
+      const workingDirectory = copyRepository()
       repo = GitRepositoryAsync.open(workingDirectory)
     })
 
@@ -487,9 +486,8 @@ describe('GitRepositoryAsync', () => {
   })
 
   describe('.getReferenceTarget(reference, path)', () => {
-    let workingDirectory
     beforeEach(() => {
-      workingDirectory = copyRepository()
+      const workingDirectory = copyRepository()
       repo = GitRepositoryAsync.open(workingDirectory)
     })
 
@@ -498,4 +496,22 @@ describe('GitRepositoryAsync', () => {
       expect(SHA).toBe('8a9c86f1cb1f14b8f436eb91f4b052c8802ca99e')
     })
   })
+
+  describe('.getConfigValue(key, path)', () => {
+    beforeEach(() => {
+      const workingDirectory = copyRepository()
+      console.log(workingDirectory)
+      repo = GitRepositoryAsync.open(workingDirectory)
+    })
+
+    it('looks up the value for the key', async () => {
+      const bare = await repo.getConfigValue('core.bare')
+      expect(bare).toBe('false')
+    })
+
+    it("resolves to null if there's no value", async () => {
+      const value = await repo.getConfigValue('my.special.key')
+      expect(value).toBe(null)
+    })
+  })
 })

src/git-repository-async.js

@@ -233,8 +233,14 @@ export default class GitRepositoryAsync {
   //
   // * `path` An optional {String} path in the repository to get this information
   //   for, only needed if the repository has submodules.
+  //
+  // Returns a {Promise} which resolves to the {String} git configuration value
+  // specified by the key.
   getConfigValue (key, _path) {
-    throw new Error('Unimplemented')
+    return this._getRepo(_path)
+      .then(repo => repo.configSnapshot())
+      .then(config => config.getStringBuf(key))
+      .catch(_ => null)
   }
 
   // Public: Returns the origin url of the repository.