updated docs

test/backend/language-tests.js

@@ -0,0 +1,67 @@
+const assert = require('assert');
+const sinon = require('sinon');
+const proxyquire = require('proxyquire').noCallThru();
+
+const config = {
+  l10n_dev: false // prod configuration
+};
+const pkg = {
+  availableLanguages: ['en-US', 'fr', 'it', 'es-ES']
+};
+
+function request(acceptLang) {
+  return {
+    headers: {
+      'accept-language': acceptLang
+    }
+  };
+}
+
+const langMiddleware = proxyquire('../../server/middleware/language', {
+  '../config': config,
+  '../../package.json': pkg
+});
+
+describe('Language Middleware', function() {
+  it('defaults to en-US when no header is present', function() {
+    const req = request();
+    const next = sinon.stub();
+    langMiddleware(req, null, next);
+    assert.equal(req.language, 'en-US');
+    sinon.assert.calledOnce(next);
+  });
+
+  it('sets req.language to en-US when accept-language > 255 chars', function() {
+    const accept = Array(257).join('a');
+    assert.equal(accept.length, 256);
+    const req = request(accept);
+    const next = sinon.stub();
+    langMiddleware(req, null, next);
+    assert.equal(req.language, 'en-US');
+    sinon.assert.calledOnce(next);
+  });
+
+  it('defaults to en-US when no accept-language is available', function() {
+    const req = request('fa,cs,ja');
+    const next = sinon.stub();
+    langMiddleware(req, null, next);
+    assert.equal(req.language, 'en-US');
+    sinon.assert.calledOnce(next);
+  });
+
+  it('prefers higher q values', function() {
+    const req = request('fa;q=0.5, it;q=0.9');
+    const next = sinon.stub();
+    langMiddleware(req, null, next);
+    assert.equal(req.language, 'it');
+    sinon.assert.calledOnce(next);
+  });
+
+  it('uses likely subtags', function() {
+    const req = request('es-MX');
+    const next = sinon.stub();
+    langMiddleware(req, null, next);
+    assert.equal(req.language, 'es-ES');
+    sinon.assert.calledOn(next);
+  });
+});