Partial implementation of node os polyfill based on currently available Deno functionality (#3821)

5 files changed, 505 insertions, 1 deletions

diff --git a/std/node/README.md b/std/node/README.md
index d0d638d05..8d9f4ff40 100644
--- a/std/node/README.md
+++ b/std/node/README.md
@@ -23,7 +23,7 @@ deno standard library as it's a compatiblity module.
 - [ ] https
 - [x] module
 - [ ] net
-- [ ] os
+- [x] os _partly_
 - [x] path
 - [ ] perf_hooks
 - [x] process _partly_
diff --git a/std/node/module.ts b/std/node/module.ts
index 599ae2325..f27ef25f2 100644
--- a/std/node/module.ts
+++ b/std/node/module.ts
@@ -25,6 +25,7 @@ import * as nodeFS from "./fs.ts";
 import * as nodeUtil from "./util.ts";
 import * as nodePath from "./path.ts";
 import * as nodeTimers from "./timers.ts";
+import * as nodeOs from "./os.ts";
 
 import * as path from "../path/mod.ts";
 import { assert } from "../testing/asserts.ts";
@@ -582,6 +583,7 @@ nativeModulePolyfill.set("fs", createNativeModule("fs", nodeFS));
 nativeModulePolyfill.set("util", createNativeModule("util", nodeUtil));
 nativeModulePolyfill.set("path", createNativeModule("path", nodePath));
 nativeModulePolyfill.set("timers", createNativeModule("timers", nodeTimers));
+nativeModulePolyfill.set("os", createNativeModule("os", nodeOs));
 function loadNativeModule(
   _filename: string,
   request: string
diff --git a/std/node/module_test.ts b/std/node/module_test.ts
index 91744d94d..a869179dd 100644
--- a/std/node/module_test.ts
+++ b/std/node/module_test.ts
@@ -42,3 +42,9 @@ test(function requireIndexJS() {
   const { isIndex } = require_("./tests/cjs");
   assert(isIndex);
 });
+
+test(function requireNodeOs() {
+  const os = require_("os");
+  assert(os.arch);
+  assert(typeof os.arch() == "string");
+});
diff --git a/std/node/os.ts b/std/node/os.ts
new file mode 100644
index 000000000..ee64bfceb
--- /dev/null
+++ b/std/node/os.ts
@@ -0,0 +1,221 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+import { notImplemented } from "./_utils.ts";
+
+const SEE_GITHUB_ISSUE = "See https://github.com/denoland/deno/issues/3802";
+
+interface CPUTimes {
+  /** The number of milliseconds the CPU has spent in user mode */
+  user: number;
+
+  /** The number of milliseconds the CPU has spent in nice mode */
+  nice: number;
+
+  /** The number of milliseconds the CPU has spent in sys mode */
+  sys: number;
+
+  /** The number of milliseconds the CPU has spent in idle mode */
+  idle: number;
+
+  /** The number of milliseconds the CPU has spent in irq mode */
+  irq: number;
+}
+
+interface CPUCoreInfo {
+  model: string;
+
+  /** in MHz */
+  speed: number;
+
+  times: CPUTimes;
+}
+
+interface NetworkAddress {
+  /** The assigned IPv4 or IPv6 address */
+  address: string;
+
+  /** The IPv4 or IPv6 network mask */
+  netmask: string;
+
+  family: "IPv4" | "IPv6";
+
+  /** The MAC address of the network interface */
+  mac: string;
+
+  /** true if the network interface is a loopback or similar interface that is not remotely accessible; otherwise false */
+  internal: boolean;
+
+  /** The numeric IPv6 scope ID (only specified when family is IPv6) */
+  scopeid?: number;
+
+  /** The assigned IPv4 or IPv6 address with the routing prefix in CIDR notation. If the netmask is invalid, this property is set to null. */
+  cidr: string;
+}
+
+interface NetworkInterfaces {
+  [key: string]: NetworkAddress[];
+}
+
+export interface UserInfoOptions {
+  encoding: string;
+}
+
+interface UserInfo {
+  username: string;
+  uid: number;
+  gid: number;
+  shell: string;
+  homedir: string;
+}
+
+/** Returns the operating system CPU architecture for which the Deno binary was compiled */
+export function arch(): string {
+  return Deno.build.arch;
+}
+
+/** Not yet implemented */
+export function cpus(): CPUCoreInfo[] {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function endianness(): "BE" | "LE" {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function freemem(): number {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function getPriority(pid = 0): number {
+  validateInt32(pid, "pid");
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Returns the string path of the current user's home directory. */
+export function homedir(): string {
+  return Deno.dir("home");
+}
+
+/** Returns the host name of the operating system as a string. */
+export function hostname(): string {
+  return Deno.hostname();
+}
+
+/** Not yet implemented */
+export function loadavg(): number[] {
+  if (Deno.build.os == "win") {
+    return [0, 0, 0];
+  }
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function networkInterfaces(): NetworkInterfaces {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function platform(): string {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function release(): string {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function setPriority(pid: number, priority?: number): void {
+  /* The node API has the 'pid' as the first parameter and as optional.  
+       This makes for a problematic implementation in Typescript. */
+  if (priority === undefined) {
+    priority = pid;
+    pid = 0;
+  }
+  validateInt32(pid, "pid");
+  validateInt32(priority, "priority", -20, 19);
+
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function tmpdir(): string {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function totalmem(): number {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function type(): string {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function uptime(): number {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+/** Not yet implemented */
+export function userInfo(
+  /* eslint-disable-next-line @typescript-eslint/no-unused-vars */
+  options: UserInfoOptions = { encoding: "utf-8" }
+): UserInfo {
+  notImplemented(SEE_GITHUB_ISSUE);
+}
+
+export const constants = {
+  // UV_UDP_REUSEADDR: 4,  //see https://nodejs.org/docs/latest-v12.x/api/os.html#os_libuv_constants
+  dlopen: {
+    // see https://nodejs.org/docs/latest-v12.x/api/os.html#os_dlopen_constants
+  },
+  errno: {
+    // see https://nodejs.org/docs/latest-v12.x/api/os.html#os_error_constants
+  },
+  signals: Deno.Signal,
+  priority: {
+    // see https://nodejs.org/docs/latest-v12.x/api/os.html#os_priority_constants
+  }
+};
+
+export const EOL = Deno.build.os == "win" ? "\r\n" : "\n";
+
+const validateInt32 = (
+  value: number,
+  name: string,
+  min = -2147483648,
+  max = 2147483647
+): void => {
+  // The defaults for min and max correspond to the limits of 32-bit integers.
+  if (!Number.isInteger(value)) {
+    throw new Error(`${name} must be 'an integer' but was ${value}`);
+  }
+  if (value < min || value > max) {
+    throw new Error(
+      `${name} must be >= ${min} && <= ${max}.  Value was ${value}`
+    );
+  }
+};
diff --git a/std/node/os_test.ts b/std/node/os_test.ts
new file mode 100644
index 000000000..88f0113ec
--- /dev/null
+++ b/std/node/os_test.ts
@@ -0,0 +1,275 @@
+import { test } from "../testing/mod.ts";
+import {
+  assert,
+  assertThrows,
+  assertEquals,
+  AssertionError
+} from "../testing/asserts.ts";
+import * as os from "./os.ts";
+
+test({
+  name: "build architecture is a string",
+  fn() {
+    assertEquals(typeof os.arch(), "string");
+  }
+});
+
+test({
+  name: "home directory is a string",
+  fn() {
+    assertEquals(typeof os.homedir(), "string");
+  }
+});
+
+test({
+  name: "hostname is a string",
+  fn() {
+    assertEquals(typeof os.hostname(), "string");
+  }
+});
+
+test({
+  name: "getPriority(): PID must be a 32 bit integer",
+  fn() {
+    assertThrows(
+      () => {
+        os.getPriority(3.15);
+      },
+      Error,
+      "pid must be 'an integer'"
+    );
+    assertThrows(
+      () => {
+        os.getPriority(9999999999);
+      },
+      Error,
+      "must be >= -2147483648 && <= 2147483647"
+    );
+  }
+});
+
+test({
+  name: "setPriority(): PID must be a 32 bit integer",
+  fn() {
+    assertThrows(
+      () => {
+        os.setPriority(3.15, 0);
+      },
+      Error,
+      "pid must be 'an integer'"
+    );
+    assertThrows(
+      () => {
+        os.setPriority(9999999999, 0);
+      },
+      Error,
+      "pid must be >= -2147483648 && <= 2147483647"
+    );
+  }
+});
+
+test({
+  name: "setPriority(): priority must be an integer between -20 and 19",
+  fn() {
+    assertThrows(
+      () => {
+        os.setPriority(0, 3.15);
+      },
+      Error,
+      "priority must be 'an integer'"
+    );
+    assertThrows(
+      () => {
+        os.setPriority(0, -21);
+      },
+      Error,
+      "priority must be >= -20 && <= 19"
+    );
+    assertThrows(
+      () => {
+        os.setPriority(0, 20);
+      },
+      Error,
+      "priority must be >= -20 && <= 19"
+    );
+    assertThrows(
+      () => {
+        os.setPriority(0, 9999999999);
+      },
+      Error,
+      "priority must be >= -20 && <= 19"
+    );
+  }
+});
+
+test({
+  name:
+    "setPriority(): if only one argument specified, then this is the priority, NOT the pid",
+  fn() {
+    assertThrows(
+      () => {
+        os.setPriority(3.15);
+      },
+      Error,
+      "priority must be 'an integer'"
+    );
+    assertThrows(
+      () => {
+        os.setPriority(-21);
+      },
+      Error,
+      "priority must be >= -20 && <= 19"
+    );
+    assertThrows(
+      () => {
+        os.setPriority(20);
+      },
+      Error,
+      "priority must be >= -20 && <= 19"
+    );
+    assertThrows(
+      () => {
+        os.setPriority(9999999999);
+      },
+      Error,
+      "priority must be >= -20 && <= 19"
+    );
+  }
+});
+
+test({
+  name: "Signals are as expected",
+  fn() {
+    // Test a few random signals for equality
+    assertEquals(os.constants.signals.SIGKILL, Deno.Signal.SIGKILL);
+    assertEquals(os.constants.signals.SIGCONT, Deno.Signal.SIGCONT);
+    assertEquals(os.constants.signals.SIGXFSZ, Deno.Signal.SIGXFSZ);
+  }
+});
+
+test({
+  name: "EOL is as expected",
+  fn() {
+    assert(os.EOL == "\r\n" || os.EOL == "\n");
+  }
+});
+
+// Method is currently implemented correctly for windows but not for any other os
+test({
+  name: "Load average is an array of 3 numbers",
+  fn() {
+    try {
+      const result = os.loadavg();
+      assert(result.length == 3);
+      assertEquals(typeof result[0], "number");
+      assertEquals(typeof result[1], "number");
+      assertEquals(typeof result[2], "number");
+    } catch (error) {
+      if (!(Object.getPrototypeOf(error) === Error.prototype)) {
+        const errMsg = `Unexpected error class: ${error.name}`;
+        throw new AssertionError(errMsg);
+      } else if (!error.message.includes("Not implemented")) {
+        throw new AssertionError(
+          "Expected this error to contain 'Not implemented'"
+        );
+      }
+    }
+  }
+});
+
+test({
+  name: "APIs not yet implemented",
+  fn() {
+    assertThrows(
+      () => {
+        os.cpus();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.endianness();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.freemem();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.getPriority();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.networkInterfaces();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.platform();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.release();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.setPriority(0);
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.tmpdir();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.totalmem();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.type();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.uptime();
+      },
+      Error,
+      "Not implemented"
+    );
+    assertThrows(
+      () => {
+        os.userInfo();
+      },
+      Error,
+      "Not implemented"
+    );
+  }
+});