fix: unwrap ESM-style process polyfills in internal streams (fixes #539)

build/build.mjs

@@ -196,6 +196,7 @@ async function main() {
   contents.push(['lib/ours/primordials.js', await readFile('src/primordials.js', 'utf-8')])
   contents.push(['lib/ours/util.js', await readFile('src/util.js', 'utf-8')])
   contents.push(['lib/ours/util/inspect.js', await readFile('src/util/inspect.js', 'utf-8')])
+  contents.push(['lib/internal/shims/process.js', await readFile('src/internal/shims/process.js', 'utf-8')])
 
   for (const file of await readdir('src/test/ours')) {
     contents.push([`test/ours/${file}`, await readFile(`src/test/ours/${file}`, 'utf-8')])

build/headers.mjs

@@ -9,7 +9,7 @@ const bufferRequire = `
 const processRequire = `
   /* replacement start */
 
-  const process = require('process/')
+  const process = require('../shims/process')
 
   /* replacement end */
 `

lib/internal/shims/process.js

@@ -0,0 +1,19 @@
+'use strict'
+
+/* wraps the internal process module, circumventing issues with some polyfills (see #539) */
+const process = ((base, esmKey, keys, isValid) => {
+  if (esmKey in base && base[esmKey] === true) {
+    let candidate
+    for (const key of keys) {
+      if (!(key in base)) {
+        continue
+      }
+      candidate = base[key]
+      if (isValid(candidate)) {
+        return candidate
+      }
+    }
+  }
+  return base
+})(require('process/'), '__esModule', ['default', 'process'], (candidate) => 'nextTick' in candidate)
+module.exports = process

lib/internal/streams/destroy.js

@@ -2,7 +2,7 @@
 
 /* replacement start */
 
-const process = require('process/')
+const process = require('../shims/process')
 
 /* replacement end */
 

lib/internal/streams/duplexify.js

@@ -1,6 +1,6 @@
 /* replacement start */
 
-const process = require('process/')
+const process = require('../shims/process')
 
 /* replacement end */
 

lib/internal/streams/end-of-stream.js

@@ -5,7 +5,7 @@
 
 /* replacement start */
 
-const process = require('process/')
+const process = require('../shims/process')
 
 /* replacement end */
 

lib/internal/streams/from.js

@@ -2,7 +2,7 @@
 
 /* replacement start */
 
-const process = require('process/')
+const process = require('../shims/process')
 
 /* replacement end */
 

lib/internal/streams/pipeline.js

@@ -1,6 +1,6 @@
 /* replacement start */
 
-const process = require('process/')
+const process = require('../shims/process')
 
 /* replacement end */
 // Ported from https://github.com/mafintosh/pump with

lib/internal/streams/readable.js

@@ -23,7 +23,7 @@
 
 /* replacement start */
 
-const process = require('process/')
+const process = require('../shims/process')
 
 /* replacement end */
 

lib/internal/streams/writable.js

@@ -27,7 +27,7 @@
 
 /* replacement start */
 
-const process = require('process/')
+const process = require('../shims/process')
 
 /* replacement end */
 

src/internal/shims/process.js

@@ -0,0 +1,21 @@
+'use strict'
+
+/* wraps the internal process module, circumventing issues with some polyfills (see #539) */
+
+const process = ((base, esmKey, keys, isValid) => {
+  if (esmKey in base && base[esmKey] === true) {
+    let candidate
+    for (const key of keys) {
+      if (!(key in base)) {
+        continue
+      }
+      candidate = base[key]
+      if (isValid(candidate)) {
+        return candidate
+      }
+    }
+  }
+  return base
+})(require('process/'), '__esModule', ['default', 'process'], (candidate) => 'nextTick' in candidate)
+
+module.exports = process

src/test/ours/test-process-shim.js

@@ -0,0 +1,54 @@
+'use strict'
+
+const t = require('tap')
+const shimPath = '../../lib/internal/shims/process'
+
+t.test('unwraps an ES module default export containing the process object', (t) => {
+  const processLike = { nextTick() {} }
+  const wrappedProcess = { __esModule: true, default: processLike }
+
+  const shimmedProcess = t.mock(shimPath, {
+    'process/': wrappedProcess
+  })
+
+  t.equal(shimmedProcess, processLike)
+  t.equal(typeof shimmedProcess.nextTick, 'function')
+  t.end()
+})
+
+t.test('unwraps an ES module process export when default is not process-like', (t) => {
+  const processLike = { nextTick() {} }
+  const wrappedProcess = { __esModule: true, default: {}, process: processLike }
+
+  const shimmedProcess = t.mock(shimPath, {
+    'process/': wrappedProcess
+  })
+
+  t.equal(shimmedProcess, processLike)
+  t.equal(typeof shimmedProcess.nextTick, 'function')
+  t.end()
+})
+
+t.test('returns a plain process-like object unchanged', (t) => {
+  const processLike = { nextTick() {} }
+
+  const shimmedProcess = t.mock(shimPath, {
+    'process/': processLike
+  })
+
+  t.equal(shimmedProcess, processLike)
+  t.equal(typeof shimmedProcess.nextTick, 'function')
+  t.end()
+})
+
+t.test('returns an ES module wrapper unchanged when no candidate is process-like', (t) => {
+  const wrappedProcess = { __esModule: true, default: {}, process: {} }
+
+  const shimmedProcess = t.mock(shimPath, {
+    'process/': wrappedProcess
+  })
+
+  t.equal(shimmedProcess, wrappedProcess)
+  t.notOk('nextTick' in shimmedProcess)
+  t.end()
+})

test/ours/test-process-shim.js

@@ -0,0 +1,59 @@
+'use strict'
+
+const t = require('tap')
+const shimPath = '../../lib/internal/shims/process'
+t.test('unwraps an ES module default export containing the process object', (t) => {
+  const processLike = {
+    nextTick() {}
+  }
+  const wrappedProcess = {
+    __esModule: true,
+    default: processLike
+  }
+  const shimmedProcess = t.mock(shimPath, {
+    'process/': wrappedProcess
+  })
+  t.equal(shimmedProcess, processLike)
+  t.equal(typeof shimmedProcess.nextTick, 'function')
+  t.end()
+})
+t.test('unwraps an ES module process export when default is not process-like', (t) => {
+  const processLike = {
+    nextTick() {}
+  }
+  const wrappedProcess = {
+    __esModule: true,
+    default: {},
+    process: processLike
+  }
+  const shimmedProcess = t.mock(shimPath, {
+    'process/': wrappedProcess
+  })
+  t.equal(shimmedProcess, processLike)
+  t.equal(typeof shimmedProcess.nextTick, 'function')
+  t.end()
+})
+t.test('returns a plain process-like object unchanged', (t) => {
+  const processLike = {
+    nextTick() {}
+  }
+  const shimmedProcess = t.mock(shimPath, {
+    'process/': processLike
+  })
+  t.equal(shimmedProcess, processLike)
+  t.equal(typeof shimmedProcess.nextTick, 'function')
+  t.end()
+})
+t.test('returns an ES module wrapper unchanged when no candidate is process-like', (t) => {
+  const wrappedProcess = {
+    __esModule: true,
+    default: {},
+    process: {}
+  }
+  const shimmedProcess = t.mock(shimPath, {
+    'process/': wrappedProcess
+  })
+  t.equal(shimmedProcess, wrappedProcess)
+  t.notOk('nextTick' in shimmedProcess)
+  t.end()
+})