Merge pull request #11 in ONE/jest-image-snapshot from feature/readme…

…-update to master

* commit 'abb4d88157330be376734616a1d4ad57d966a675':
  docs(readme): update for new custom snapshots dir option

README.md

@@ -38,7 +38,7 @@ Jest matcher that performs image comparisons using [pixelmatch](https://github.c
 * `customDiffConfig`: Custom config passed [pixelmatch](https://github.com/mapbox/pixelmatch#pixelmatchimg1-img2-output-width-height-options) (See options section)
   * By default we have set the `threshold` to 0.01, you can increase that value by passing a customDiffConfig as demonstrated below.
   * Please note the `threshold` set in the `customDiffConfig` is the per pixel sensitivity threshold. For example with a source pixel colour of `#ffffff` (white) and a comparison pixel colour of `#fcfcfc` (really light grey) if you set the threshold to 0 then it would trigger a failure *on that pixel*. However if you were to use say 0.5 then it wouldn't, the colour difference would need to be much more extreme to trigger a failure on that pixel, say `#000000` (black)
-* `customSnapshotsDir`: A custom directory to keep this snapshot in
+* `customSnapshotsDir`: (default: `__image_snapshots__`) A custom directory to keep this snapshot in
 * `customSnapshotIdentifier`: A custom name to give this snapshot. If not provided one is computed automatically
 * `noColors`: (default `false`) Removes colouring from console output, useful if storing the results in a file
 * `failureThreshold`: (default `0`) Sets the threshold that would trigger a test failure based on the `failureThresholdType` selected. This is different to the `customDiffConfig.threshold` above, that is the per pixel failure threshold, this is the failure threshold for the entire comparison.
@@ -82,7 +82,7 @@ expect.extend({ toMatchImageSnapshot });
 ```
 
 ## How it works
-  Given an image (should be either a PNGImage instance or a Buffer instance with PNG data) the `toMatchImageSnapshot()` matcher will create a `__image_snapshots__` directory in the directory the test is in and will store the baseline snapshot image there on the first run.
+  Given an image (should be either a PNGImage instance or a Buffer instance with PNG data) the `toMatchImageSnapshot()` matcher will create a `__image_snapshots__` directory in the directory the test is in and will store the baseline snapshot image there on the first run. Note that if `customSnapshotsDir` option is given then it will store baseline snapshot there instead.
 
   On subsequent test runs the matcher will compare the image being passed against the stored snapshot.