Merge branch 'master' of github.com:DCzajkowski/snapshy

.travis.yml

@@ -0,0 +1,16 @@
+language: elixir
+
+sudo: false
+
+matrix:
+  include:
+    - otp_release: 21.0
+      elixir: 1.8.1
+
+script:
+  - mix format --check-formatted
+  - mix test --trace
+
+cache:
+  directories:
+    - priv/plts

README.md

@@ -1,21 +1,62 @@
 # Snapshy
 
-**TODO: Add description**
+Snapshy is an Elixir package for running snapshot tests in ExUnit. More extensive documentation is coming soon.
 
 ## Installation
 
-If [available in Hex](https://hex.pm/docs/publish), the package can be installed
-by adding `snapshy` to your list of dependencies in `mix.exs`:
+Add `snapshy` to your list of dependencies in `mix.exs` and run `mix deps.get`:
 
 ```elixir
 def deps do
   [
+    # ...
     {:snapshy, "~> 0.1.0"}
   ]
 end
 ```
 
-Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
-and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
-be found at [https://hexdocs.pm/snapshy](https://hexdocs.pm/snapshy).
+## Overview
 
+The way this works:
+
+1. Add Snapshy to the test
+
+```diff
+ defmodule TokenizerTest do
++  use Snapshy
+   use ExUnit.Case
+
+   # ...
+ end
+```
+
+2. Replace `test` with `test_snapshot`
+
+```diff
+-  test "correctly tokenizes booleans" do
++  test_snapshot "correctly tokenizes booleans" do
+     # ...
+   end
+```
+
+3. Replace an assertion with simple function call
+
+```diff
+-    assert(
+-      tokens("true false") == [
+-        boolean: "true",
+-        boolean: "false"
+-      ]
+-    )
++    tokens("true false")
+```
+
+The first time a snapshot will be created in `test/__snapshots__/path/to/test_file/function_name.stub`. The second time, an assertion will be made against the snapshot. If you make changes and you want to update snapshots, run `SNAPSHY_OVERRIDE=true mix test` instead of `mix test`. Verify in git every change is correct.
+
+Alternatively, you can use a macro call instead of the `test_snapshot` macro like so:
+```elixir
+test "correctly tokenizes booleans" do
+  match_snapshot tokens("true false")
+end
+```
+**Careful!** There can only be one `match_snapshot` call per test macro call.