Issue #286: Add "two dot" notation for "git log".

Add unit test "with non-symmetric from and to" and modify the Readme.

readme.md

@@ -61,7 +61,7 @@ when no error occurred) and secondly the data generated by that call.
 | `.getRemotes([verbose], handlerFn)` | gets a list of the named remotes, when the verbose option is supplied as true, includes the URLs and purpose of each ref |
 | `.init(bare, handlerFn)` | initialize a repository, optional `bare` parameter makes intialized repository bare |
 | `.listRemote([args], handlerFn)` | lists remote repositories - there are so many optional arguments in the underlying  `git ls-remote` call, just supply any you want to use as the optional `args` array of strings eg: `git.listRemote(['--heads', '--tags'], console.log.bind(console))` |
-| `.log([options], handlerFn)` | list commits between `options.from` and `options.to` tags or branch (if not specified will show all history). Additionally you can provide `options.file`, which is the path to a file in your repository. Then only this file will be considered. For any other set of options, supply `options` as an array of strings to be appended to the `git log` command. To use a custom splitter in the log format, set `options.splitter` to be the string the log should be split on. Options can also be supplied as a standard [options](#how-to-specify-options) object for adding custom properties supported by the [git log](https://git-scm.com/docs/git-log) command. |
+| `.log([options], handlerFn)` | list commits between `options.from` and `options.to` tags or branch (if not specified will show all history). Additionally you can provide `options.file`, which is the path to a file in your repository. Then only this file will be considered. `option.symmetrc` allows you to specify whether you want to use [symmetric revision range](https://git-scm.com/docs/gitrevisions#_dotted_range_notations) (To be compatible, by default, its value is true). For any other set of options, supply `options` as an array of strings to be appended to the `git log` command. To use a custom splitter in the log format, set `options.splitter` to be the string the log should be split on. Options can also be supplied as a standard [options](#how-to-specify-options) object for adding custom properties supported by the [git log](https://git-scm.com/docs/git-log) command. |
 | `.mergeFromTo(from, to, [[options,] handlerFn])` | merge from one branch to another, when supplied the options should be an array of additional parameters to pass into the [git merge](https://git-scm.com/docs/git-merge) command |
 | `.merge(options, handlerFn)` | runs a merge, `options` can be either an array of arguments supported by the [git merge](https://git-scm.com/docs/git-merge) command or an [options](#how-to-specify-options) object. Conflicts during the merge result in an error response, the response type whether it was an error or success will be a [MergeSummary](src/responses/MergeSummary.js) instance. When successful, the MergeSummary has all detail from a the [PullSummary](src/responses/PullSummary.js) |
 | `.mirror(repoPath, localPath, handlerFn])` | clone and mirror the repo to local |

test/unit/test-log.js

@@ -74,6 +74,34 @@ exports.log = {
       closeWith('');
    },
 
+   'with explicit symmetric from and to' (test) {
+      git.log({
+         from: 'from',
+         to: 'to',
+         symmetric: true
+      }, function (err) {
+         test.equals(null, err, 'not an error');
+         test.same(["log", `--pretty=format:%H;%ai;%s;%D;%b;%aN;%ae${commitSplitter}`, "from...to"], theCommandRun());
+         test.done();
+      });
+
+      closeWith('');
+   },
+
+   'with non-symmetric from and to' (test) {
+      git.log({
+         from: 'from',
+         to: 'to',
+         symmetric: false
+      }, function (err) {
+         test.equals(null, err, 'not an error');
+         test.same(["log", `--pretty=format:%H;%ai;%s;%D;%b;%aN;%ae${commitSplitter}`, "from..to"], theCommandRun());
+         test.done();
+      });
+
+      closeWith('');
+   },
+
    'with options array' (test) {
       git.log(['--some=thing'], function (err, result) {
          test.equals(null, err, 'not an error');