feat(volume): add env variable to suppress fs.promise api warnings

To suppress experimental fs.promise api warnings the SUPRESS_EXPERIMENTAL_PROMISE_WARNINGS env variable can be set to a truthy value

docs/reference.md

@@ -139,3 +139,11 @@ you get from `require('fs')`. Here are some things this function does:
   ```
 
   - Adds constants `fs.constants`, `fs.F_OK`, etc.
+
+## Experimental fs.promise api warnings
+
+Supress warnings when using the promise api of fs by setting
+
+```js
+process.env['SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS'] = true;
+```

src/__tests__/process.test.ts

@@ -1,4 +1,4 @@
-import _process, { createProcess } from '../process';
+import _process, { createProcess, SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS } from '../process';
 
 describe('process', () => {
   describe('createProcess', () => {
@@ -17,5 +17,15 @@ describe('process', () => {
       expect(typeof proc.nextTick).toBe('function');
       proc.nextTick(done);
     });
+    it('.env', () => {
+      expect(typeof proc.env).toBe('object');
+      expect(!!proc.env[SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS]).toBe(false);
+    });
+  });
+  test('createProcess with env variable', () => {
+    process.env[SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS] = 'true';
+    const proc = createProcess();
+    expect(!!proc.env[SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS]).toBe(true);
+    delete process.env[SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS];
   });
 });

src/process.ts

@@ -1,11 +1,18 @@
 // Here we mock the global `process` variable in case we are not in Node's environment.
 
+export type SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS = 'SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS';
+export const SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS: SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS =
+  'SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS';
+
 export interface IProcess {
   getuid(): number;
   getgid(): number;
   cwd(): string;
   platform: string;
   nextTick: (callback: (...args) => void, ...args) => void;
+  env: {
+    [SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS]?: boolean;
+  };
 }
 
 export function createProcess(p: IProcess = process): IProcess {
@@ -20,6 +27,7 @@ export function createProcess(p: IProcess = process): IProcess {
   if (!p.getgid) p.getgid = () => 0;
   if (!p.cwd) p.cwd = () => '/';
   if (!p.nextTick) p.nextTick = require('./setImmediate').default;
+  if (!p.env) p.env = {};
   return p;
 }
 

src/volume.ts

@@ -4,7 +4,7 @@ import Stats, { TStatNumber } from './Stats';
 import Dirent from './Dirent';
 import { Buffer } from 'buffer';
 import setImmediate from './setImmediate';
-import process from './process';
+import process, { SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS } from './process';
 import setTimeoutUnref, { TSetTimeout } from './setTimeoutUnref';
 import { Readable, Writable } from 'stream';
 import { constants } from './constants';
@@ -516,7 +516,7 @@ function validateGid(gid: number) {
 
 // ---------------------------------------- Volume
 
-let promisesWarn = true;
+let promisesWarn = process[SUPPRESS_EXPERIMENTAL_PROMISE_WARNINGS] ? false : true;
 
 /**
  * `Volume` represents a file system.