Implement composite Git strategy

lib/composite-git-strategy.js

@@ -0,0 +1,22 @@
+import os from 'os';
+
+import {firstImplementer} from './helpers';
+import AsyncQueue from './async-queue';
+import GitShellOutStrategy from './git-shell-out-strategy';
+
+export default {
+  create(workingDir, options = {}) {
+    return this.withStrategies([GitShellOutStrategy])(workingDir, options);
+  },
+
+  withStrategies(strategies) {
+    return function createForStrategies(workingDir, options = {}) {
+      const parallelism = options.parallelism || Math.max(3, os.cpus().length);
+      const commandQueue = new AsyncQueue({parallelism});
+      const strategyOptions = {...options, queue: commandQueue};
+
+      const strategyInstances = strategies.map(Strategy => new Strategy(workingDir, strategyOptions));
+      return firstImplementer(...strategyInstances);
+    };
+  },
+};

lib/git-shell-out-strategy.js

@@ -35,8 +35,13 @@ export default class GitShellOutStrategy {
 
   constructor(workingDir, options = {}) {
     this.workingDir = workingDir;
-    const parallelism = options.parallelism || Math.max(3, os.cpus().length);
-    this.commandQueue = new AsyncQueue({parallelism});
+    if (options.queue) {
+      this.commandQueue = options.queue;
+    } else {
+      const parallelism = options.parallelism || Math.max(3, os.cpus().length);
+      this.commandQueue = new AsyncQueue({parallelism});
+    }
+
   }
 
   // Execute a command and read the output using the embedded Git environment

lib/helpers.js

@@ -1,6 +1,68 @@
 import fs from 'fs-extra';
 import {ncp} from 'ncp';
 
+
+function descriptorsFromProto(proto) {
+  return Object.getOwnPropertyNames(proto).reduce((acc, name) => {
+    Object.assign(acc, {
+      [name]: Reflect.getOwnPropertyDescriptor(proto, name),
+    });
+    return acc;
+  }, {});
+}
+
+/**
+ * Takes an array of targets and returns a proxy. The proxy intercepts property accessor calls and
+ * returns the value of that property on the first object in `targets` where the target implements that property.
+ */
+export function firstImplementer(...targets) {
+  return new Proxy({__implementations: targets}, {
+    get(target, name) {
+      if (Reflect.has(target, name)) {
+        return target[name];
+      }
+
+      const firstValidTarget = targets.find(t => Reflect.has(t, name));
+      if (firstValidTarget) {
+        return firstValidTarget[name];
+      } else {
+        return undefined;
+      }
+    },
+
+    set(target, name, value) {
+      const firstValidTarget = targets.find(t => Reflect.has(t, name));
+      if (firstValidTarget) {
+        // eslint-disable-next-line no-return-assign
+        return firstValidTarget[name] = value;
+      } else {
+        // eslint-disable-next-line no-return-assign
+        return target[name] = value;
+      }
+    },
+
+    // Used by sinon
+    getOwnPropertyDescriptor(target, name) {
+      const firstValidTarget = targets.find(t => Reflect.getOwnPropertyDescriptor(t, name));
+      const compositeOwnPropertyDescriptor = Reflect.getOwnPropertyDescriptor(target, name);
+      if (firstValidTarget) {
+        return Reflect.getOwnPropertyDescriptor(firstValidTarget, name);
+      } else if (compositeOwnPropertyDescriptor) {
+        return compositeOwnPropertyDescriptor;
+      } else {
+        return undefined;
+      }
+    },
+
+    // Used by sinon
+    getPrototypeOf(target) {
+      return targets.reduceRight((acc, t) => {
+        return Object.create(acc, descriptorsFromProto(Object.getPrototypeOf(t)));
+      }, Object.prototype);
+    },
+  });
+}
+
 export function readFile(absoluteFilePath, encoding = 'utf8') {
   return new Promise((resolve, reject) => {
     fs.readFile(absoluteFilePath, encoding, (err, contents) => {

lib/models/repository.js

@@ -3,7 +3,7 @@ import path from 'path';
 import {Emitter, Disposable} from 'atom';
 import {autobind} from 'core-decorators';
 
-import GitShellOutStrategy from '../git-shell-out-strategy';
+import CompositeGitStrategy from '../composite-git-strategy';
 import FilePatch from './file-patch';
 import Hunk from './hunk';
 import HunkLine from './hunk-line';
@@ -33,7 +33,7 @@ export class CommitError extends Error {
 
 export default class Repository {
   static async open(workingDirectoryPath, gitStrategy) {
-    const strategy = gitStrategy || new GitShellOutStrategy(workingDirectoryPath);
+    const strategy = gitStrategy || CompositeGitStrategy.create(workingDirectoryPath);
     if (await strategy.isGitRepository()) {
       const historySha = await strategy.getConfig('atomGithub.historySha');
       const history = historySha ? JSON.parse(await strategy.getBlobContents(historySha)) : {};

lib/views/git-timings-view.js

@@ -138,11 +138,19 @@ class MarkerSpan extends React.Component {
     });
   }
 
-  @autobind
-  handleMouseOut(e) {
+  closeTooltip() {
     this.tooltipDisposable && this.tooltipDisposable.dispose();
     this.tooltipDisposable = null;
   }
+
+  @autobind
+  handleMouseOut(e) {
+    this.closeTooltip();
+  }
+
+  componentWillUnmount() {
+    this.closeTooltip();
+  }
 }