feat(core): Filter requests matched by a route handler (#189)

Author: offirgolan

docs/server/route-handler.md

@@ -170,30 +170,37 @@ server.any('/session').passthrough();
 server.get('/session/1').passthrough(false);
 ```
 
-### recordingName
+### filter
 
-Override the recording name for the given route. This allows for grouping common
-requests to share a single recording which can drastically help de-clutter test
-recordings.
+Filter requests matched by the route handler with a predicate callback function.
+This can be useful when trying to match a request by a part of the url, a header,
+and/or parts of the request body.
 
-For example, if your tests always make a `/users` or `/session` call, instead of
-having each of those requests be recorded for every single test, you can use
-this to create a common recording file for them.
+The callback will receive the [Request](server/request)
+as an argument. Return `true` to match the request, `false` otherwise.
 
-| Param         | Type     | Description                                                               |
-| ------------- | -------- | ------------------------------------------------------------------------- |
-| recordingName | `String` | Name of the [recording](api#recordingName) to store the recordings under. |
+?> Multiple filters can be chained together. They must all return `true` for the route handler to match the given request.
+
+| Param    | Type       | Description                   |
+| -------- | ---------- | ----------------------------- |
+| callback | `Function` | The filter predicate function |
 
 **Example**
 
 ```js
-server.any('/session').recordingName('User Session');
-
-server.get('/users/:id').recordingName('User Data');
+server
+  .any()
+  .filter(req => req.hasHeader('Authentication'));
+  .on('request', req => {
+    res.setHeader('Authentication', 'test123')
+  });
 
 server
-  .get('/users/1')
-  .recordingName(); /* Fallback to the polly instance's recording name */
+  .get('/users/:id')
+  .filter(req => req.params.id === '1');
+  .intercept((req, res) => {
+    res.status(200).json({ email: '[email protected]' });
+  });
 ```
 
 ### configure
@@ -217,3 +224,29 @@ server.get('/users/:id').configure({ timing: Timing.relative(3.0) });
 
 server.get('/users/1').configure({ logging: true });
 ```
+
+### recordingName
+
+Override the recording name for the given route. This allows for grouping common
+requests to share a single recording which can drastically help de-clutter test
+recordings.
+
+For example, if your tests always make a `/users` or `/session` call, instead of
+having each of those requests be recorded for every single test, you can use
+this to create a common recording file for them.
+
+| Param         | Type     | Description                                                               |
+| ------------- | -------- | ------------------------------------------------------------------------- |
+| recordingName | `String` | Name of the [recording](api#recordingName) to store the recordings under. |
+
+**Example**
+
+```js
+server.any('/session').recordingName('User Session');
+
+server.get('/users/:id').recordingName('User Data');
+
+server
+  .get('/users/1')
+  .recordingName(); /* Fallback to the polly instance's recording name */
+```

packages/@pollyjs/adapter-fetch/tests/integration/server-test.js

@@ -49,40 +49,158 @@ describe('Integration | Server', function() {
     expect(numIntercepts).to.equal(2);
   });
 
-  it('merges all configs', async function() {
-    const { server } = this.polly;
-    let config;
-
-    server.any().configure({ foo: 'foo' });
-    server.any().configure({ bar: 'bar' });
-    server
-      .get('/ping')
-      .configure({ foo: 'baz' })
-      .intercept((req, res) => {
-        config = req.config;
-        res.sendStatus(200);
-      });
+  describe('API', function() {
+    it('.configure() - merges all configs', async function() {
+      const { server } = this.polly;
+      let config;
 
-    expect((await fetch('/ping')).status).to.equal(200);
-    expect(config).to.include({ foo: 'baz', bar: 'bar' });
-  });
+      server.any().configure({ foo: 'foo' });
+      server.any().configure({ bar: 'bar' });
+      server
+        .get('/ping')
+        .configure({ foo: 'baz' })
+        .intercept((req, res) => {
+          config = req.config;
+          res.sendStatus(200);
+        });
 
-  it('should throw when trying to override certain options', async function() {
-    const { server } = this.polly;
+      expect((await fetch('/ping')).status).to.equal(200);
+      expect(config).to.include({ foo: 'baz', bar: 'bar' });
+    });
+
+    it('.configure() - should throw when trying to override certain options', async function() {
+      const { server } = this.polly;
+
+      // The following options cannot be overridden on a per request basis
+      [
+        'mode',
+        'adapters',
+        'adapterOptions',
+        'persister',
+        'persisterOptions'
+      ].forEach(key =>
+        expect(() => server.any().configure({ [key]: 'foo' })).to.throw(
+          Error,
+          /Invalid configuration option/
+        )
+      );
+    });
+
+    it('.recordingName()', async function() {
+      const { server } = this.polly;
+      let recordingName;
+
+      server
+        .get('/ping')
+        .recordingName('Override')
+        .intercept((req, res) => {
+          recordingName = req.recordingName;
+          res.sendStatus(200);
+        });
+
+      expect((await fetch('/ping')).status).to.equal(200);
+      expect(recordingName).to.equal('Override');
+    });
+
+    it('.recordingName() - should reset when called with no arguments', async function() {
+      const { server } = this.polly;
+      let recordingName;
+
+      server.any().recordingName('Override');
+
+      server
+        .get('/ping')
+        .recordingName()
+        .intercept((req, res) => {
+          recordingName = req.recordingName;
+          res.sendStatus(200);
+        });
+
+      expect((await fetch('/ping')).status).to.equal(200);
+      expect(recordingName).to.not.equal('Override');
+    });
+
+    it('.filter()', async function() {
+      const { server } = this.polly;
 
-    // The following options cannot be overridden on a per request basis
-    [
-      'mode',
-      'adapters',
-      'adapterOptions',
-      'persister',
-      'persisterOptions'
-    ].forEach(key =>
-      expect(() => server.any().configure({ [key]: 'foo' })).to.throw(
+      server
+        .get('/ping')
+        .filter(req => req.query.num === '1')
+        .intercept((req, res) => res.sendStatus(201));
+
+      server
+        .get('/ping')
+        .filter(req => req.query.num === '2')
+        .intercept((req, res) => res.sendStatus(202));
+
+      expect((await fetch('/ping?num=1')).status).to.equal(201);
+      expect((await fetch('/ping?num=2')).status).to.equal(202);
+    });
+
+    it('.filter() + events', async function() {
+      const { server } = this.polly;
+      let num;
+
+      server
+        .get('/ping')
+        .filter(req => req.query.num === '1')
+        .on('request', req => (num = req.query.num))
+        .intercept((req, res) => res.sendStatus(201));
+
+      server
+        .get('/ping')
+        .filter(req => req.query.num === '2')
+        .on('request', req => (num = req.query.num))
+        .intercept((req, res) => res.sendStatus(202));
+
+      expect((await fetch('/ping?num=1')).status).to.equal(201);
+      expect(num).to.equal('1');
+    });
+
+    it('.filter() - multiple', async function() {
+      const { server } = this.polly;
+
+      server
+        .get('/ping')
+        .filter(req => req.query.foo === 'foo')
+        .filter(req => req.query.bar === 'bar')
+        .intercept((req, res) => res.sendStatus(201));
+
+      server
+        .get('/ping')
+        .filter(req => req.query.foo === 'foo')
+        .filter(req => req.query.baz === 'baz')
+        .intercept((req, res) => res.sendStatus(202));
+
+      expect((await fetch('/ping?foo=foo&bar=bar')).status).to.equal(201);
+      expect((await fetch('/ping?foo=foo&baz=baz')).status).to.equal(202);
+    });
+
+    it('.filter() - can access params', async function() {
+      const { server } = this.polly;
+      let id;
+
+      server
+        .get('/ping/:id')
+        .filter(req => {
+          id = req.params.id;
+
+          return true;
+        })
+        .intercept((req, res) => res.sendStatus(201));
+
+      expect((await fetch('/ping/1')).status).to.equal(201);
+      expect(id).to.equal('1');
+    });
+
+    it('.filter() - should throw when not passed a function', async function() {
+      const { server } = this.polly;
+
+      expect(() => server.any().filter()).to.throw(
         Error,
-        /Invalid configuration option/
-      )
-    );
+        /Invalid filter callback provided/
+      );
+    });
   });
 
   describe('Events & Middleware', function() {

packages/@pollyjs/core/src/-private/request.js

@@ -57,6 +57,9 @@ export default class PollyRequest extends HTTPBase {
     // Lookup the associated route for this request
     this[ROUTE] = polly.server.lookup(this.method, this.url);
 
+    // Filter all matched route handlers by this request
+    this[ROUTE].applyFiltersWithArgs(this);
+
     // Handle config overrides defined by the route
     this._configure(this[ROUTE].config());
 

packages/@pollyjs/core/src/server/handler.js

@@ -11,6 +11,7 @@ export default class Handler extends Map {
     super();
 
     this.set('config', {});
+    this.set('filters', new Set());
     this._eventEmitter = new EventEmitter({
       eventNames: [
         'error',
@@ -79,4 +80,15 @@ export default class Handler extends Map {
 
     return this;
   }
+
+  filter(fn) {
+    assert(
+      `Invalid filter callback provided. Expected function, received: "${typeof fn}".`,
+      typeof fn === 'function'
+    );
+
+    this.get('filters').add(fn);
+
+    return this;
+  }
 }