Add tests

.gitignore

@@ -1,2 +1,5 @@
 node_modules/
 .DS_Store
+yarn.lock
+coverage/
+.nyc_output

package.json

@@ -7,7 +7,9 @@
     "jsesc": "^2.3.0",
     "regenerate": "^1.3.2"
   },
-  "devDependencies": {},
+  "devDependencies": {
+    "mocha": "^3.2.0"
+  },
   "scripts": {
     "test": "mocha"
   },

test/test.js

@@ -0,0 +1,40 @@
+const assert = require('assert');
+const regexgen = require('../');
+
+describe('regexgen', function () {
+  it('should generate a char class', function () {
+    assert.deepEqual(regexgen(['a', 'b', 'c']), /[a-c]/);
+  });
+
+  it('should generate an alternation', function () {
+    assert.deepEqual(regexgen(['abc', '123']), /123|abc/);
+  });
+
+  it('should extract common prefixes at the start', function () {
+    assert.deepEqual(regexgen(['foobar', 'foozap']), /foo(?:zap|bar)/);
+  });
+
+  it('should extract common prefixes at the end', function () {
+    assert.deepEqual(regexgen(['barfoo', 'zapfoo']), /(?:zap|bar)foo/);
+  });
+
+  it('should extract common prefixes at the start and end', function () {
+    assert.deepEqual(regexgen(['foobarfoo', 'foozapfoo']), /foo(?:zap|bar)foo/);
+  });
+
+  it('should generate an optional group', function () {
+    assert.deepEqual(regexgen(['foo', 'foobar']), /foo(?:bar)?/);
+  });
+
+  it('should generate multiple optional groups', function () {
+    assert.deepEqual(regexgen(['f', 'fo', 'fox']), /f(?:ox?)?/);
+  });
+
+  it('should escape meta characters', function () {
+    assert.deepEqual(regexgen(['foo|bar[test]+']), /foo\|bar\[test\]\+/);
+  });
+
+  it('should escape non-ascii characters', function () {
+    assert.deepEqual(regexgen(['🎉']), /\uD83C\uDF89/);
+  })
+});