feat(commit): add --retry option

This adds an option to git cz --retry the latest commit. This is useful if you go through the
prompts but your tests fail.

Closes #132

package.json

@@ -72,6 +72,7 @@
     "glob": "7.0.3",
     "gulp": "3.9.1",
     "gulp-git": "1.7.0",
+    "home-or-tmp": "2.0.0",
     "inquirer": "0.12.0",
     "lodash": "4.6.1",
     "minimist": "1.2.0",

src/cli/strategies/git-cz.js

@@ -38,6 +38,11 @@ function gitCz(rawGitArgs, environment, adapterConfig) {
 
   // Now, if we've made it past overrides, proceed with the git-cz strategy
   let parsedGitCzArgs = parse(rawGitArgs);
+
+  // Determine if we need to process this commit as a retry instead of a
+  // normal commit.
+  let retryLastCommit = rawGitArgs && rawGitArgs[0] === '--retry';
+
   let resolvedAdapterConfigPath = resolveAdapterPath(adapterConfig.path);
   let resolvedAdapterRootPath = findRoot(resolvedAdapterConfigPath);
   let prompter = getPrompter(adapterConfig.path);
@@ -50,7 +55,7 @@ function gitCz(rawGitArgs, environment, adapterConfig) {
       let adapterPackageJson = getParsedPackageJsonFromPath(resolvedAdapterRootPath);
       let cliPackageJson = getParsedPackageJsonFromPath(environment.cliPath);
       console.log(`cz-cli@${cliPackageJson.version}, ${adapterPackageJson.name}@${adapterPackageJson.version}\n`);
-      commit(sh, inquirer, process.cwd(), prompter, {args: parsedGitCzArgs, disableAppendPaths:true, emitData:true, quiet:false}, function() {
+      commit(sh, inquirer, process.cwd(), prompter, {args: parsedGitCzArgs, disableAppendPaths:true, emitData:true, quiet:false, retryLastCommit}, function() {
         // console.log('commit happened');
       });
 

src/commitizen.js

@@ -1,11 +1,13 @@
 import * as adapter from './commitizen/adapter';
+import * as cache from './commitizen/cache';
 import commit from './commitizen/commit';
 import * as configLoader from './commitizen/configLoader';
 import init from './commitizen/init';
 import * as staging from './commitizen/staging';
 
 export {
   adapter,
+  cache,
   commit,
   configLoader,
   init,

src/commitizen/cache.js

@@ -0,0 +1,44 @@
+import fs from 'fs';
+import _ from 'lodash';
+
+export {
+  getCacheValueSync,
+  readCacheSync,
+  setCacheValueSync,
+};
+
+/**
+ * Reads the entire cache
+ */
+function readCacheSync(cachePath) {
+  return JSON.parse(fs.readFileSync(cachePath, 'utf8'));
+}
+
+/**
+ * Sets a cache value and writes the file to disk
+ */
+function setCacheValueSync(cachePath, key, value) {
+  var originalCache;
+  try {
+    originalCache = readCacheSync(cachePath); 
+  } catch (e) {
+    originalCache = {};
+  }
+  var newCache = Object.assign(originalCache, {
+    [key]: value
+  });
+  fs.writeFileSync(cachePath, JSON.stringify(newCache, null, '  '));
+  return newCache;
+}
+
+/**
+ * Gets a single value from the cache given a key
+ */
+function getCacheValueSync(cachePath, repoPath) {
+  try {
+    let cache = readCacheSync(cachePath);
+    return cache[repoPath];
+  } catch(e) {
+    return;
+  }
+}

src/commitizen/commit.js

@@ -1,20 +1,51 @@
+import path from 'path';
+import homeOrTmp from 'home-or-tmp';
 import dedent from 'dedent';
 import {commit as gitCommit, log} from '../git';
+import * as cache from './cache';
 
 export default commit;
-
+
+/**
+ * Takes all of the final inputs needed in order to make dispatch a git commit
+ */
+function dispatchGitCommit(sh, repoPath, template, options, overrideOptions, done) {
+
+    // Commit the user input -- side effect that we'll test
+    gitCommit(sh, repoPath, template, { ...options, ...overrideOptions }, function() {
+      done(template);
+    });
+
+}
+
  /**
   * Asynchronously commits files using commitizen
   */
 function commit(sh, inquirer, repoPath, prompter, options, done) {
 
-  // Get user input -- side effect that is hard to test
-  prompter(inquirer, function(template, overrideOptions) {
+  var cachePath = path.join(homeOrTmp, 'commitizen.json');
+
+  if(options.retryLastCommit) {
 
-    // Commit the user input -- side effect that we'll test
-    gitCommit(sh, repoPath, template, { ...options, ...overrideOptions }, function() {
-      done(template);
-    });
-  });
+    console.log('Retrying last commit attempt.');
+
+    // We want to use the last commit instead of the current commit,
+    // so lets override some options using the values from cache.
+    let { 
+      options: retryOptions,
+      overrideOptions: retryOverrideOptions,
+      template: retryTemplate
+    } = cache.getCacheValueSync(cachePath, repoPath);
+    dispatchGitCommit(sh, repoPath, retryTemplate, retryOptions, retryOverrideOptions, done);
+
+  } else {
+    // Get user input -- side effect that is hard to test
+    prompter(inquirer, function(template, overrideOptions) {
+
+      // We don't want to add retries to the cache, only actual commands
+      cache.setCacheValueSync(cachePath, repoPath, { template, options, overrideOptions });
+      dispatchGitCommit(sh, repoPath, template, options, overrideOptions, done);
+    }); 
+  }
 
 }