git helper functions (WIP) #47

lib/git.js

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2018 Adobe. All rights reserved.
+ * This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License. You may obtain a copy
+ * of the License at http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under
+ * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ * OF ANY KIND, either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+
+'use strict';
+
+const git = require('isomorphic-git');
+
+git.plugins.set('fs', require('fs'));
+
+/**
+ * Various helper functions reading git content
+ */
+
+/**
+ * Returns the contents of the file at revision `ref` and `pathName`
+ *
+ * @param {string} dir git repo path
+ * @param {string} ref reference (branch, tag or commit sha)
+ * @param {string} filePath relative path to file
+ * @param {boolean} dirty whether modified file should be returned
+ * @returns {Promise<Buffer>} content of specified file
+ */
+async function getRawContent(dir, ref, pathName, dirty) {
+  // TODO: implement serveUncommitted logic
+  let commitSha;
+  try {
+    commitSha = await git.resolveRef({ dir, ref });
+  } catch (err) {
+    if (err.code === 'ResolveRefError') {
+      // fallback: is ref a shortened oid prefix?
+      const oid = await git.expandOid({ dir, oid: ref });
+      commitSha = await git.resolveRef({ dir, ref: oid });
+    } else {
+      throw err;
+    }
+  }
+  const content = await git.readObject({
+    dir,
+    oid: commitSha,
+    filepath: pathName,
+    format: 'content',
+  });
+  return content;
+}
+
+module.exports = {
+  getRawContent,
+};