Refactor to use this project as a module

You don't always have to use the CLI. Add a bunch of unit tests

Author: piuccio

.eslintignore

@@ -0,0 +1 @@
+lib/__tests__/scripts/syntax.js

.eslintrc.json

@@ -1,8 +1,12 @@
 {
     "env": {
+        "es6": true,
         "node": true
     },
     "extends": "eslint:recommended",
+    "parserOptions": {
+        "ecmaVersion": 6
+    },
     "rules": {
         "no-console": 0
     }

README.md

@@ -8,9 +8,11 @@ It's preferable to install it globally through [`npm`](https://www.npmjs.com/pac
 
     npm install -g git-release-notes
 
+It's also possible to use `git-release-notes` as a node module. Check the usage on [usage as a module](#Usage_as_a_module)
+
 ### Usage
 
-The basic usage is
+The basic usage from the command line is
 
     cd <your_git_project>
     git-release-notes <since>..<until> <template>
@@ -69,7 +71,7 @@ More advanced options are
 * `f` or `file` JSON Configuration file, better option when you don't want to pass all parameters to the command line, for an example see [options.json](https://github.com/ariatemplates/git-release-notes/blob/master/options.json)
 * `s` or `script` External script for post-processing commits
 * `c` or `merge-commits` List only merge commits, `git log` command is executed with the `--merges` flag instead of `--no-merges`
-* `o` or `gitlog-option` to add some additional git log options **and** ignores the `merge-commits` option, this is direct given to `git log` by adding a `--` to each longname option from the array (e.g. `-o first-parent`). 
+* `o` or `gitlog-option` to add some additional git log options **and** ignores the `merge-commits` option, this is direct given to `git log` by adding a `--` to each longname option from the array (e.g. `-o first-parent`).
 
 #### Title Parsing
 
@@ -133,18 +135,51 @@ The object passed to the callback will be merged with the input data and passed
 
 For an example check `samples/post-processing.js`
 
+
+### Usage as a module
+
+#### Installation
+
+   npm install --save-dev git-release-notes
+
+#### Usage
+
+Inside your script file
+
+```js
+const releaseNotes = require('git-release-notes');
+
+const OPTIONS = {
+  branch: 'master',
+};
+const RANGE = 'v1.0.0..v2.0.0';
+const TEMPLATE = 'markdown';
+
+releaseNotes(OPTIONS, RANGE, TEMPLATE)
+.then((changelog) => {
+  console.log(`Changelog between ${RANGE}\n\n${changelog}`);
+})
+.catch((ex) => {
+  console.error(ex);
+  process.exit(1);
+});
+```
+
+#### Options
+
+The syntax reflects the command line parameters, so options is an object containing `path`, `branch`, `title` and so on. You can refer to the list of options in the command line usage section. You can use either the long or short syntax, the module will use the same defaults as the command line if an option is missing.
+
+
 ### Debug
 If your post processing script or template throws an exception, the JSON data will be written to the file system in the same folder as the processing script.
 
 The DEBUG environment variable can also be useful for fault diagnosis:
 
 #### Linux
-    DEBUG=release-notes:*
+    export DEBUG=release-notes:*
     git-release-notes ...
 
 #### Windows
 
     SET DEBUG=release-notes:cli,release-notes:externalscript
     git-release-notes ...
-
-Note the filtering options available: `release-notes:cli`, `release-notes:externalscript`, `release-notes:data`

cli.js

@@ -0,0 +1,62 @@
+#!/usr/bin/env node
+var argv = require("optimist").usage("git-release-notes [<options>] <since>..<until> <template>")
+.options("f", {
+	"alias": "file"
+})
+.options("p", {
+	"alias": "path",
+	"default": process.cwd()
+})
+.options("t", {
+	"alias": "title",
+	"default": "(.*)"
+})
+.boolean("i")
+.alias("i", "ignore-case")
+.options("m", {
+	"alias": "meaning",
+	"default": ['type']
+})
+.options("b", {
+	"alias": "branch",
+	"default": "master"
+})
+.options("s", {
+	"alias": "script"
+})
+.options("o", {
+	"alias": "gitlog-option",
+	"default" : []
+})
+.boolean("c")
+.alias("c", "merge-commits")
+.describe({
+	"f": "Configuration file",
+	"p": "Git project path",
+	"t": "Commit title regular expression",
+	"i": "Ignore case of title's regular expression",
+	"m": "Meaning of capturing block in title's regular expression",
+	"b": "Git branch, defaults to master",
+	"s": "External script to rewrite the commit history",
+	"c": "Only use merge commits",
+	"o": "Additional git log options AND ignore 'c' option"
+})
+.boolean("version")
+.check(function (argv) {
+	if (argv._.length == 2) {
+		return true;
+	}
+	throw "Invalid parameters, please specify an interval and the template";
+})
+.argv;
+
+const index = require('./index');
+index(argv, argv._[0], argv._[1])
+.then(function (output) {
+  process.stdout.write(output + "\n");
+})
+.catch(function (error) {
+  require("optimist").showHelp();
+  console.error('\n', error.message);
+  process.exit(1);
+});

index.js

@@ -1,190 +1,35 @@
-#!/usr/bin/env node
-var argv = require("optimist").usage("git-release-notes [<options>] <since>..<until> <template>")
-.options("f", {
-	"alias": "file"
-})
-.options("p", {
-	"alias": "path",
-	"default": process.cwd()
-})
-.options("t", {
-	"alias": "title",
-	"default": "(.*)"
-})
-.boolean("i")
-.alias("i", "ignore-case")
-.options("m", {
-	"alias": "meaning",
-	"default": ['type']
-})
-.options("b", {
-	"alias": "branch",
-	"default": "master"
-})
-.options("s", {
-	"alias": "script"
-})
-.options("o", {
-	"alias": "gitlog-option",
-	"default" : []
-})
-.boolean("c")
-.alias("c", "merge-commits")
-.describe({
-	"f": "Configuration file",
-	"p": "Git project path",
-	"t": "Commit title regular expression",
-	"i": "Ignore case of title's regular expression",
-	"m": "Meaning of capturing block in title's regular expression",
-	"b": "Git branch, defaults to master",
-	"s": "External script to rewrite the commit history",
-	"c": "Only use merge commits",
-	"o": "Additional git log options AND ignore 'c' option"
-})
-.boolean("version")
-.check(function (argv) {
-	if (argv._.length == 2) {
-		return true;
-	}
-	throw "Invalid parameters, please specify an interval and the template";
-})
-.argv;
-
 var git = require("./lib/git");
-var fs = require("fs");
 var ejs = require("ejs");
-var path = require("path");
 var debug = require("debug")("release-notes:cli");
-var debugData = require("debug")("release-notes:data");
-var dateFnsFormat = require('date-fns/format')
-
-var template = argv._[1];
-debug("Trying to locate template '%s'", template);
-if (!fs.existsSync(template)) {
-	debug("Template file '%s' doesn't exist, maybe it's template name", template);
-	// Template name?
-	if (template.match(/[a-z]+(\.ejs)?/)) {
-		template = path.resolve(__dirname, "./templates/" + path.basename(template, ".ejs") + ".ejs");
-	} else {
-		require("optimist").showHelp();
-		console.error("\nUnable to locate template file " + template);
-		process.exit(1);
-	}
-}
-
-debug("Trying to locate script '%s'", argv.s);
-if (argv.s && !fs.existsSync(argv.s)) {
-	debug("Script file '%s' doesn't exist");
-	require("optimist").showHelp();
-	console.error("\nExternal script must be a valid path " + argv.s);
-	process.exit(1);
-}
+var fileSystem = require('./lib/file-system');
+var processCommits = require('./lib/process').processCommits;
+var dateFnsFormat = require('date-fns/format');
 
-debug("Trying to read template '%s'", template);
-fs.readFile(template, function (err, templateContent) {
-	if (err) {
-		require("optimist").showHelp();
-		console.error("\nUnable to locate template file " + argv._[1]);
-		process.exit(5);
-	} else {
-		getOptions(function (options) {
-			debug("Running git log in '%s' on branch '%s' with range '%s'", options.p, options.b, argv._[0]);
-			git.log({
+module.exports = function module(cliOptions, positionalRange, positionalTemplate) {
+	return fileSystem.resolveTemplate(positionalTemplate).then(function (template) {
+		return fileSystem.resolveOptions(cliOptions).then(function (options) {
+			debug("Running git log in '%s' on branch '%s' with range '%s'", options.p, options.b, positionalRange);
+			return git.log({
 				branch: options.b,
-				range: argv._[0],
+				range: positionalRange,
 				title: options.i ? new RegExp(options.t, 'i') : new RegExp(options.t),
 				meaning: Array.isArray(options.m) ? options.m: [options.m],
 				cwd: options.p,
 				mergeCommits: options.c,
 				additionalOptions: Array.isArray(options.o) ? options.o : [options.o]
-			}, function (commits) {
-				postProcess(templateContent, commits);
+			}).then(function (commits) {
+				return processCommits(options, commits, positionalRange);
+			}).then(function (data) {
+				return render(positionalRange, template, data);
 			});
 		});
-	}
-});
-
-function getOptions (callback) {
-	if (argv.f) {
-		debug("Trying to read configuration file '%s'", argv.f);
-		fs.readFile(argv.f, function (err, data) {
-			if (err) {
-				console.error("Unable to read configuration file\n" + err.message);
-			} else {
-				var options;
-				try {
-					var stored = JSON.parse(data);
-					options = {
-						b: stored.b || stored.branch || argv.b,
-						t: stored.t || stored.title || argv.t,
-						i: stored.i || stored.ignoreCase || argv.i,
-						m: stored.m || stored.meaning || argv.m,
-						o: stored.o || stored.gitlogOption || argv.o,
-						p: stored.p || stored.path || argv.p,
-						c: stored.c || stored.mergeCommits || argv.c
-					};
-				} catch (ex) {
-					console.error("Invalid JSON in configuration file");
-				}
-				if (options) {
-					callback(options);
-				}
-			}
-		});
-	} else {
-		callback(argv);
-	}
-}
-
-function postProcess(templateContent, commits) {
-	debug("Got %d commits", commits.length);
-	if (commits.length) {
-		if (argv.s) {
-			var externalScriptPath = argv.s;
-			try {
-				var externalScript = require(externalScriptPath);
-			} catch (ex) {
-				debug("Exception while reading external script '%s': '%s'", externalScriptPath, ex.message);
-				console.error('Unable to read external script');
-				process.exit(7);
-			}
-			debug("Trying to run the external script");
-			var inputData;
-			var outputData;
-			try {
-				inputData = {
-					commits: commits,
-					range: argv._[0],
-					dateFnsFormat: dateFnsFormat,
-					debug: require("debug")("release-notes:externalscript")
-				};
-				externalScript(inputData, function (data) {
-					outputData = data;
-					render(templateContent, data);
-				});
-				debug("Waiting for external script to call the callback");
-			} catch (ex) {
-				debug("Exception while running external script '%s'", ex.message);
-				debugData("Input data passed to the external script `%s`", JSON.stringify(inputData, null, '  '));
-				debugData("Output data received from the external script `%s`", outputData ? JSON.stringify(outputData, null, '  ') : '');
-				console.error('Error while processing external script', ex);
-				process.exit(8);
-			}
-		} else {
-			debug("Rendering template without post processing");
-			render(templateContent, { commits: commits });
-		}
-	} else {
-		console.error('No commits in the specified range');
-		process.exit(6);
-	}
-}
+	});
+};
 
-function render(templateContent, data) {
+function render(range, templateContent, data) {
 	debug("Rendering template");
-	var output = ejs.render(templateContent.toString(), Object.assign({
-		range: argv._[0],
+	return ejs.render(templateContent, Object.assign({
+		range: range,
 		dateFnsFormat: dateFnsFormat
 	}, data));
-	process.stdout.write(output + "\n");
 }