rewrite nodegit specific code using isomorphic-git (WIP) #47

lib/blobHandler.js

@@ -12,8 +12,7 @@
 
 'use strict';
 
-const Git = require('nodegit');
-
+const { getBlob } = require('./git');
 const { resolveRepositoryPath } = require('./utils');
 
 /**
@@ -43,35 +42,36 @@ function createMiddleware(options) {
 
     const repPath = resolveRepositoryPath(options, owner, repoName);
 
-    let repo;
-    Git.Repository.open(repPath)
-      .then((repository) => {
-        repo = repository;
-        return repo.getBlob(sha);
-      })
+    if (sha.match(/[0-9a-f]/g).length !== 40) {
+      // invalid sha format
+      res.status(422).json({
+        message: 'The sha parameter must be exactly 40 characters and contain only [0-9a-f].',
+        documentation_url: 'https://developer.github.com/v3/git/blobs/#get-a-blob',
+      });
+      return;
+    }
+    getBlob(repPath, sha)
       .then(((blob) => {
         res.json({
-          sha,
-          size: blob.rawsize(),
+          sha: blob.oid,
+          size: blob.size,
           url: `${req.protocol}://${host}${req.path}`,
-          content: `${blob.content().toString('base64')}\n`,
+          content: `${blob.content.toString('base64')}\n`,
           encoding: 'base64',
         });
       }))
       .catch((err) => {
-        if (err.errno === -3) {
+        // TODO: use generic errors
+        if (err.code === 'ReadObjectFail') {
           options.logger.debug(`[blobHandler] resource not found: ${err.message}`);
           res.status(404).json({
             message: 'Not Found',
+            documentation_url: 'https://developer.github.com/v3/git/blobs/#get-a-blob',
           });
         } else {
-          options.logger.debug(`[blobHandler] errno: ${err.errno} errorFuntion: ${err.errorFunction} message: ${err.message} stack: ${err.stack}`);
+          options.logger.debug(`[blobHandler] code: ${err.code} message: ${err.message} stack: ${err.stack}`);
           next(err);
         }
-      })
-      .finally(() => {
-        // TODO: cache Repository instances (key: absolute path)
-        repo.free();
       });
   };
 }

lib/git.js

@@ -24,6 +24,16 @@ git.plugins.set('fs', require('fs'));
  * Various helper functions for reading git meta-data and content
  */
 
+/**
+ * Returns the name (abbreviated form) of the currently checked out branch.
+ *
+ * @param {string} dir git repo path
+ * @returns {Promise<string>} name of the currently checked out branch
+ */
+async function currentBranch(dir) {
+  return git.currentBranch({ dir, fullname: false });
+}
+
 /**
  * Determines whether the specified reference is currently checked out in the working dir.
  *
@@ -128,9 +138,24 @@ async function createBlobReadStream(dir, oid) {
   return stream;
 }
 
+/**
+ * Returns a stream for reading the specified blob.
+ *
+ * @param {string} dir git repo path
+ * @param {string} id blob id (sha1)
+ * @returns {Promise<Object>} object containing `oid` (string), `size` (number)
+ *                            and `content` (Buffer)
+ */
+async function getBlob(dir, id) {
+  const content = await git.readObject({ dir, oid: id, format: 'content' });
+  return { oid: id, content: content.object, size: content.object.length };
+}
+
 module.exports = {
+  currentBranch,
   getRawContent,
   resolveBlob,
   isCheckedOut,
   createBlobReadStream,
+  getBlob,
 };

lib/rawHandler.js

@@ -62,6 +62,7 @@ function createMiddleware(options) {
           .then(stream => stream.pipe(res));
       })
       .catch((err) => {
+        // TODO: use abstract errors
         if (err.code === 'TreeOrBlobNotFoundError') {
           options.logger.debug(`[rawHandler] resource not found: ${err.message}`);
           res.status(404).send('not found.');

lib/server.js

@@ -18,12 +18,12 @@ const https = require('https');
 const util = require('util');
 
 const fse = require('fs-extra');
-const Git = require('nodegit');
 const pem = require('pem');
 const _ = require('lodash');
 
 let logger = require('./logger');
 const app = require('./app');
+const git = require('./git');
 const { resolveRepositoryPath } = require('./utils');
 
 const DEFAULT_REPO_ROOT = './repos';
@@ -225,9 +225,7 @@ async function start(rawConfig) {
 async function getRepoInfo(rawConfig, owner, repo) {
   const cfg = rawConfig || await readConfiguration();
   const repPath = resolveRepositoryPath(await initConfiguration(cfg), owner, repo);
-  const rep = await Git.Repository.open(repPath);
-  const currentBranch = (await rep.head()).shorthand();
-  rep.free();
+  const currentBranch = await git.currentBranch(repPath);
   return { owner, repo, currentBranch };
 }