✨ In testing mode, clear logs on reset (#989)

During testing mode, full logs are rarely useful, but individual snapshot logs are more important to
test against. Clearing logs on reset will allow SDK tests to read only recent and relevant logs
without having to filter them.

packages/core/src/api.js

@@ -102,8 +102,9 @@ export function createPercyServer(percy, port) {
       body = Buffer.isBuffer(body) ? body.toString() : body;
 
       if (cmd === 'reset') {
-        // the reset command will reset testing mode to its default options
+        // the reset command will reset testing mode and clear any logs
         percy.testing = {};
+        logger.instance.messages.clear();
       } else if (cmd === 'version') {
         // the version command will update the api version header for testing
         percy.testing.version = body;

packages/core/test/api.test.js

@@ -257,6 +257,19 @@ describe('API Server', () => {
       expect(percy.dryRun).toBeTrue();
     });
 
+    it('enables a /test/snapshot endpoint that serves a simple html document', async () => {
+      await expectAsync(get('/test/snapshot')).toBeResolvedTo('<p>Snapshot Me!</p>');
+    });
+
+    it('enables a /test/logs endpoint to return raw logs', async () => {
+      percy.log.info('foo bar from test');
+      let { logs } = await get('/test/logs');
+
+      expect(logs).toEqual(jasmine.arrayContaining([
+        jasmine.objectContaining({ message: 'foo bar from test' })
+      ]));
+    });
+
     it('enables several /test/api endpoint commands', async () => {
       expect(percy.testing).toEqual({});
       await post('/test/api/version', false);
@@ -300,17 +313,22 @@ describe('API Server', () => {
       await expectAsync(req('/percy/healthcheck')).toBeRejected();
     });
 
-    it('enables a /test/logs endpoint to return raw logs', async () => {
+    it('can reset testing mode and clear logs via /test/reset', async () => {
+      // already tested up above
+      await post('/test/api/version', false);
+      await post('/test/api/disconnect', '/percy/healthcheck');
       percy.log.info('foo bar from test');
-      let { logs } = await get('/test/logs');
 
-      expect(logs).toEqual(jasmine.arrayContaining([
-        jasmine.objectContaining({ message: 'foo bar from test' })
-      ]));
-    });
+      // the actual endpoint to test
+      await post('/test/api/reset');
 
-    it('enables a /test/snapshot endpoint that serves a simple html document', async () => {
-      await expectAsync(get('/test/snapshot')).toBeResolvedTo('<p>Snapshot Me!</p>');
+      // everything should work as usual
+      let { headers } = await req('/percy/healthcheck');
+      expect(headers['x-percy-core-version']).toBeDefined();
+
+      // logs should be empty after reset
+      let { logs } = await get('/test/logs');
+      expect(logs).toEqual([]);
     });
   });
 });