1 files changed, 307 insertions, 0 deletions
diff --git a/cli/js/process.ts b/cli/js/process.ts
new file mode 100644
index 000000000..0c77929f9
--- /dev/null
+++ b/cli/js/process.ts
@@ -0,0 +1,307 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import { sendSync, sendAsync } from "./dispatch_json.ts";
+import * as dispatch from "./dispatch.ts";
+import { File, close } from "./files.ts";
+import { ReadCloser, WriteCloser } from "./io.ts";
+import { readAll } from "./buffer.ts";
+import { assert, unreachable } from "./util.ts";
+import { build } from "./build.ts";
+
+/** How to handle subprocess stdio.
+ *
+ * "inherit" The default if unspecified. The child inherits from the
+ * corresponding parent descriptor.
+ *
+ * "piped"  A new pipe should be arranged to connect the parent and child
+ * subprocesses.
+ *
+ * "null" This stream will be ignored. This is the equivalent of attaching the
+ * stream to /dev/null.
+ */
+export type ProcessStdio = "inherit" | "piped" | "null";
+
+// TODO Maybe extend VSCode's 'CommandOptions'?
+// See https://code.visualstudio.com/docs/editor/tasks-appendix#_schema-for-tasksjson
+export interface RunOptions {
+  args: string[];
+  cwd?: string;
+  env?: { [key: string]: string };
+  stdout?: ProcessStdio | number;
+  stderr?: ProcessStdio | number;
+  stdin?: ProcessStdio | number;
+}
+
+interface RunStatusResponse {
+  gotSignal: boolean;
+  exitCode: number;
+  exitSignal: number;
+}
+
+async function runStatus(rid: number): Promise<ProcessStatus> {
+  const res = (await sendAsync(dispatch.OP_RUN_STATUS, {
+    rid
+  })) as RunStatusResponse;
+
+  if (res.gotSignal) {
+    const signal = res.exitSignal;
+    return { signal, success: false };
+  } else {
+    const code = res.exitCode;
+    return { code, success: code === 0 };
+  }
+}
+
+/** Send a signal to process under given PID. Unix only at this moment.
+ * If pid is negative, the signal will be sent to the process group identified
+ * by -pid.
+ * Requires the `--allow-run` flag.
+ */
+export function kill(pid: number, signo: number): void {
+  sendSync(dispatch.OP_KILL, { pid, signo });
+}
+
+export class Process {
+  readonly rid: number;
+  readonly pid: number;
+  readonly stdin?: WriteCloser;
+  readonly stdout?: ReadCloser;
+  readonly stderr?: ReadCloser;
+
+  // @internal
+  constructor(res: RunResponse) {
+    this.rid = res.rid;
+    this.pid = res.pid;
+
+    if (res.stdinRid && res.stdinRid > 0) {
+      this.stdin = new File(res.stdinRid);
+    }
+
+    if (res.stdoutRid && res.stdoutRid > 0) {
+      this.stdout = new File(res.stdoutRid);
+    }
+
+    if (res.stderrRid && res.stderrRid > 0) {
+      this.stderr = new File(res.stderrRid);
+    }
+  }
+
+  async status(): Promise<ProcessStatus> {
+    return await runStatus(this.rid);
+  }
+
+  /** Buffer the stdout and return it as Uint8Array after EOF.
+   * You must set stdout to "piped" when creating the process.
+   * This calls close() on stdout after its done.
+   */
+  async output(): Promise<Uint8Array> {
+    if (!this.stdout) {
+      throw new Error("Process.output: stdout is undefined");
+    }
+    try {
+      return await readAll(this.stdout);
+    } finally {
+      this.stdout.close();
+    }
+  }
+
+  /** Buffer the stderr and return it as Uint8Array after EOF.
+   * You must set stderr to "piped" when creating the process.
+   * This calls close() on stderr after its done.
+   */
+  async stderrOutput(): Promise<Uint8Array> {
+    if (!this.stderr) {
+      throw new Error("Process.stderrOutput: stderr is undefined");
+    }
+    try {
+      return await readAll(this.stderr);
+    } finally {
+      this.stderr.close();
+    }
+  }
+
+  close(): void {
+    close(this.rid);
+  }
+
+  kill(signo: number): void {
+    kill(this.pid, signo);
+  }
+}
+
+export interface ProcessStatus {
+  success: boolean;
+  code?: number;
+  signal?: number; // TODO: Make this a string, e.g. 'SIGTERM'.
+}
+
+// TODO: this method is only used to validate proper option, probably can be renamed
+function stdioMap(s: string): string {
+  switch (s) {
+    case "inherit":
+    case "piped":
+    case "null":
+      return s;
+    default:
+      return unreachable();
+  }
+}
+
+function isRid(arg: unknown): arg is number {
+  return !isNaN(arg as number);
+}
+
+interface RunResponse {
+  rid: number;
+  pid: number;
+  stdinRid: number | null;
+  stdoutRid: number | null;
+  stderrRid: number | null;
+}
+/**
+ * Spawns new subprocess.
+ *
+ * Subprocess uses same working directory as parent process unless `opt.cwd`
+ * is specified.
+ *
+ * Environmental variables for subprocess can be specified using `opt.env`
+ * mapping.
+ *
+ * By default subprocess inherits stdio of parent process. To change that
+ * `opt.stdout`, `opt.stderr` and `opt.stdin` can be specified independently -
+ * they can be set to either `ProcessStdio` or `rid` of open file.
+ */
+export function run(opt: RunOptions): Process {
+  assert(opt.args.length > 0);
+  let env: Array<[string, string]> = [];
+  if (opt.env) {
+    env = Array.from(Object.entries(opt.env));
+  }
+
+  let stdin = stdioMap("inherit");
+  let stdout = stdioMap("inherit");
+  let stderr = stdioMap("inherit");
+  let stdinRid = 0;
+  let stdoutRid = 0;
+  let stderrRid = 0;
+
+  if (opt.stdin) {
+    if (isRid(opt.stdin)) {
+      stdinRid = opt.stdin;
+    } else {
+      stdin = stdioMap(opt.stdin);
+    }
+  }
+
+  if (opt.stdout) {
+    if (isRid(opt.stdout)) {
+      stdoutRid = opt.stdout;
+    } else {
+      stdout = stdioMap(opt.stdout);
+    }
+  }
+
+  if (opt.stderr) {
+    if (isRid(opt.stderr)) {
+      stderrRid = opt.stderr;
+    } else {
+      stderr = stdioMap(opt.stderr);
+    }
+  }
+
+  const req = {
+    args: opt.args.map(String),
+    cwd: opt.cwd,
+    env,
+    stdin,
+    stdout,
+    stderr,
+    stdinRid,
+    stdoutRid,
+    stderrRid
+  };
+
+  const res = sendSync(dispatch.OP_RUN, req) as RunResponse;
+  return new Process(res);
+}
+
+// From `kill -l`
+enum LinuxSignal {
+  SIGHUP = 1,
+  SIGINT = 2,
+  SIGQUIT = 3,
+  SIGILL = 4,
+  SIGTRAP = 5,
+  SIGABRT = 6,
+  SIGBUS = 7,
+  SIGFPE = 8,
+  SIGKILL = 9,
+  SIGUSR1 = 10,
+  SIGSEGV = 11,
+  SIGUSR2 = 12,
+  SIGPIPE = 13,
+  SIGALRM = 14,
+  SIGTERM = 15,
+  SIGSTKFLT = 16,
+  SIGCHLD = 17,
+  SIGCONT = 18,
+  SIGSTOP = 19,
+  SIGTSTP = 20,
+  SIGTTIN = 21,
+  SIGTTOU = 22,
+  SIGURG = 23,
+  SIGXCPU = 24,
+  SIGXFSZ = 25,
+  SIGVTALRM = 26,
+  SIGPROF = 27,
+  SIGWINCH = 28,
+  SIGIO = 29,
+  SIGPWR = 30,
+  SIGSYS = 31
+}
+
+// From `kill -l`
+enum MacOSSignal {
+  SIGHUP = 1,
+  SIGINT = 2,
+  SIGQUIT = 3,
+  SIGILL = 4,
+  SIGTRAP = 5,
+  SIGABRT = 6,
+  SIGEMT = 7,
+  SIGFPE = 8,
+  SIGKILL = 9,
+  SIGBUS = 10,
+  SIGSEGV = 11,
+  SIGSYS = 12,
+  SIGPIPE = 13,
+  SIGALRM = 14,
+  SIGTERM = 15,
+  SIGURG = 16,
+  SIGSTOP = 17,
+  SIGTSTP = 18,
+  SIGCONT = 19,
+  SIGCHLD = 20,
+  SIGTTIN = 21,
+  SIGTTOU = 22,
+  SIGIO = 23,
+  SIGXCPU = 24,
+  SIGXFSZ = 25,
+  SIGVTALRM = 26,
+  SIGPROF = 27,
+  SIGWINCH = 28,
+  SIGINFO = 29,
+  SIGUSR1 = 30,
+  SIGUSR2 = 31
+}
+
+/** Signals numbers. This is platform dependent.
+ */
+export const Signal = {};
+
+export function setSignals(): void {
+  if (build.os === "mac") {
+    Object.assign(Signal, MacOSSignal);
+  } else {
+    Object.assign(Signal, LinuxSignal);
+  }
+}