Method start

lib/command.ts:198–253

* Starts this command, piping output, error and close events onto the corresponding observables.

()

     * Starts this command, piping output, error and close events onto the corresponding observables.
     */
    start() {
        const child = this.spawn(this.command, this.spawnOpts);
        this.changeState('started');
        this.process = child;
        this.pid = child.pid;
        const startDate = new Date(Date.now());
        const highResStartTime = process.hrtime();
        this.timer.next({ startDate });

        this.subscriptions = [...this.maybeSetupIPC(child)];
        Rx.fromEvent(child, 'error').subscribe((event) => {
            this.cleanUp();
            const endDate = new Date(Date.now());
            this.timer.next({ startDate, endDate });
            this.error.next(event);
            this.changeState('errored');
        });
        Rx.fromEvent(child, 'close')
            .pipe(Rx.map((event) => event as [number | null, NodeJS.Signals | null]))
            .subscribe(([exitCode, signal]) => {
                this.cleanUp();

                // Don't override error event
                if (this.state !== 'errored') {
                    this.changeState('exited');
                }

                const endDate = new Date(Date.now());
                this.timer.next({ startDate, endDate });
                const [durationSeconds, durationNanoSeconds] = process.hrtime(highResStartTime);
                this.close.next({
                    command: this,
                    index: this.index,
                    exitCode: exitCode ?? String(signal),
                    killed: this.killed,
                    timings: {
                        startDate,
                        endDate,
                        durationSeconds: durationSeconds + durationNanoSeconds / 1e9,
                    },
                });
            });
        if (child.stdout) {
            pipeTo(
                Rx.fromEvent(child.stdout, 'data').pipe(Rx.map((event) => event as Buffer)),
                this.stdout,
            );
        }
        if (child.stderr) {
            pipeTo(
                Rx.fromEvent(child.stderr, 'data').pipe(Rx.map((event) => event as Buffer)),
                this.stderr,
            );
        }
        this.stdin = child.stdin || undefined;
    }

    private changeState(state: Exclude<CommandState, 'stopped'>) {