fix: The web-ext run process can be suspended again (#948)

Author: saintsebastian

src/cmd/run.js

@@ -113,6 +113,7 @@ export type ReloadStrategyOptions = {|
   createWatcher?: WatcherCreatorFn,
   createFileFilter?: FileFilterCreatorFn,
   stdin: stream$Readable,
+  kill: typeof process.kill;
 |};
 
 export function defaultReloadStrategy(
@@ -124,6 +125,7 @@ export function defaultReloadStrategy(
     addonReload = defaultAddonReload,
     createWatcher = defaultWatcherCreator,
     stdin = process.stdin,
+    kill = process.kill,
   }: ReloadStrategyOptions = {}
 ): void {
   const watcher: Watchpack = createWatcher({
@@ -143,8 +145,11 @@ export function defaultReloadStrategy(
     // NOTE: this `Promise.resolve().then(...)` is basically used to spawn a "co-routine" that is executed
     // before the callback attached to the Promise returned by this function (and it allows the `run` function
     // to not be stuck in the while loop).
+
+    const keypressUsageInfo = 'Press R to reload (and Ctrl-C to quit)';
+
     Promise.resolve().then(async function() {
-      log.info('Press R to reload (and Ctrl-C to quit)');
+      log.info(keypressUsageInfo);
 
       let userExit = false;
 
@@ -155,6 +160,25 @@ export function defaultReloadStrategy(
 
         if (keyPressed.ctrl && keyPressed.name === 'c') {
           userExit = true;
+        } else if (keyPressed.ctrl && keyPressed.name === 'z') {
+          // Prepare to suspend.
+
+          // NOTE: Switch the raw mode off before suspending (needed to make the keypress event to work correctly
+          // when the nodejs process is resumed).
+          if (stdin instanceof tty.ReadStream) {
+            stdin.setRawMode(false);
+          }
+
+          log.info('\nweb-ext has been suspended on user request');
+          kill(process.pid, 'SIGTSTP');
+
+          // Prepare to resume.
+
+          log.info(`\nweb-ext has been resumed. ${keypressUsageInfo}`);
+          // Switch the raw mode on on resume.
+          if (stdin instanceof tty.ReadStream) {
+            stdin.setRawMode(true);
+          }
         } else if (keyPressed.name === 'r' && addonId) {
           log.debug('Reloading extension on user request');
           await addonReload({addonId, client});

tests/unit/test-cmd/test.run.js

@@ -385,6 +385,17 @@ describe('run', () => {
       kill = sinon.spy(() => {});
     }
 
+    function loopExiter(stdin) {
+      return () => stdin.emit('keypress', 'c', {name: 'c', ctrl: true});
+    }
+
+    function exitLoopOnError(stdin) {
+      return (error) => {
+        loopExiter(stdin);
+        throw error;
+      };
+    }
+
     function prepare() {
       const client = new RemoteFirefox(fakeFirefoxClient());
       const watcher = {
@@ -403,6 +414,7 @@ describe('run', () => {
         addonReload: sinon.spy(() => Promise.resolve()),
         createWatcher: sinon.spy(() => watcher),
         stdin: new stream.Readable(),
+        kill: sinon.spy(() => Promise.resolve()),
       };
       return {
         ...args,
@@ -462,19 +474,42 @@ describe('run', () => {
           assert.ok(addonReload.called);
           assert.equal(addonReload.firstCall.args[0].addonId,
             tempInstallResult.addon.id);
-        });
+        })
+        .then(loopExiter(fakeStdin), exitLoopOnError(fakeStdin));
     });
 
     it('shuts down firefox on user request (CTRL+C in shell console)', () => {
       const {firefoxProcess, reloadStrategy} = prepare();
       const fakeStdin = new tty.ReadStream();
+      sinon.spy(fakeStdin, 'setRawMode');
 
       return reloadStrategy({}, {stdin: fakeStdin})
         .then(() => {
           fakeStdin.emit('keypress', 'c', {name: 'c', ctrl: true});
         }).then(() => {
           assert.ok(firefoxProcess.kill.called);
-        });
+        })
+        .then(loopExiter(fakeStdin), exitLoopOnError(fakeStdin));
+    });
+
+    it('pauses the web-ext process (CTRL+Z in shell console)', () => {
+      const {reloadStrategy, kill} = prepare();
+      const fakeStdin = new tty.ReadStream();
+      const setRawMode = sinon.spy(fakeStdin, 'setRawMode');
+
+      return reloadStrategy({}, {stdin: fakeStdin})
+        .then(() => {
+          fakeStdin.emit('keypress', 'z', {name: 'z', ctrl: true});
+        }).then(() => {
+          assert.ok(kill.called);
+          assert.deepEqual(kill.firstCall.args, [process.pid, 'SIGTSTP']);
+          sinon.assert.callOrder(setRawMode, setRawMode, kill, setRawMode);
+          sinon.assert.calledThrice(setRawMode);
+          assert.equal(setRawMode.firstCall.args[0], true);
+          assert.equal(setRawMode.secondCall.args[0], false);
+          assert.equal(setRawMode.lastCall.args[0], true);
+        })
+        .then(loopExiter(fakeStdin), exitLoopOnError(fakeStdin));
     });
 
   });