[backport 11.x] process: move setup of process warnings into node.js

lib/internal/bootstrap/node.js

@@ -112,7 +112,15 @@ function startup() {
     process.exit = wrapped.exit;
   }
 
-  NativeModule.require('internal/process/warning').setup();
+  const {
+    onWarning,
+    emitWarning
+  } = NativeModule.require('internal/process/warning');
+  if (!process.noProcessWarnings && process.env.NODE_NO_WARNINGS !== '1') {
+    process.on('warning', onWarning);
+  }
+  process.emitWarning = emitWarning;
+
   const {
     nextTick,
     runNextTicks

lib/internal/process/warning.js

@@ -3,8 +3,6 @@
 const prefix = `(${process.release.name}:${process.pid}) `;
 const { ERR_INVALID_ARG_TYPE } = require('internal/errors').codes;
 
-exports.setup = setupProcessWarnings;
-
 let options;
 function lazyOption(name) {
   if (!options) {
@@ -85,79 +83,80 @@ function doEmitWarning(warning) {
   };
 }
 
-function setupProcessWarnings() {
-  if (!process.noProcessWarnings && process.env.NODE_NO_WARNINGS !== '1') {
-    process.on('warning', (warning) => {
-      if (!(warning instanceof Error)) return;
-      const isDeprecation = warning.name === 'DeprecationWarning';
-      if (isDeprecation && process.noDeprecation) return;
-      const trace = process.traceProcessWarnings ||
-                    (isDeprecation && process.traceDeprecation);
-      var msg = prefix;
-      if (warning.code)
-        msg += `[${warning.code}] `;
-      if (trace && warning.stack) {
-        msg += `${warning.stack}`;
-      } else {
-        const toString =
-          typeof warning.toString === 'function' ?
-            warning.toString : Error.prototype.toString;
-        msg += `${toString.apply(warning)}`;
-      }
-      if (typeof warning.detail === 'string') {
-        msg += `\n${warning.detail}`;
-      }
-      output(msg);
-    });
+function onWarning(warning) {
+  if (!(warning instanceof Error)) return;
+  const isDeprecation = warning.name === 'DeprecationWarning';
+  if (isDeprecation && process.noDeprecation) return;
+  const trace = process.traceProcessWarnings ||
+                (isDeprecation && process.traceDeprecation);
+  var msg = prefix;
+  if (warning.code)
+    msg += `[${warning.code}] `;
+  if (trace && warning.stack) {
+    msg += `${warning.stack}`;
+  } else {
+    const toString =
+      typeof warning.toString === 'function' ?
+        warning.toString : Error.prototype.toString;
+    msg += `${toString.apply(warning)}`;
   }
+  if (typeof warning.detail === 'string') {
+    msg += `\n${warning.detail}`;
+  }
+  output(msg);
+}
 
-  // process.emitWarning(error)
-  // process.emitWarning(str[, type[, code]][, ctor])
-  // process.emitWarning(str[, options])
-  process.emitWarning = (warning, type, code, ctor, now) => {
-    let detail;
-    if (type !== null && typeof type === 'object' && !Array.isArray(type)) {
-      ctor = type.ctor;
-      code = type.code;
-      if (typeof type.detail === 'string')
-        detail = type.detail;
-      type = type.type || 'Warning';
-    } else if (typeof type === 'function') {
-      ctor = type;
-      code = undefined;
-      type = 'Warning';
-    }
-    if (type !== undefined && typeof type !== 'string') {
-      throw new ERR_INVALID_ARG_TYPE('type', 'string', type);
-    }
-    if (typeof code === 'function') {
-      ctor = code;
-      code = undefined;
-    } else if (code !== undefined && typeof code !== 'string') {
-      throw new ERR_INVALID_ARG_TYPE('code', 'string', code);
-    }
-    if (typeof warning === 'string') {
-      // Improve error creation performance by skipping the error frames.
-      // They are added in the `captureStackTrace()` function below.
-      const tmpStackLimit = Error.stackTraceLimit;
-      Error.stackTraceLimit = 0;
-      // eslint-disable-next-line no-restricted-syntax
-      warning = new Error(warning);
-      Error.stackTraceLimit = tmpStackLimit;
-      warning.name = String(type || 'Warning');
-      if (code !== undefined) warning.code = code;
-      if (detail !== undefined) warning.detail = detail;
-      Error.captureStackTrace(warning, ctor || process.emitWarning);
-    } else if (!(warning instanceof Error)) {
-      throw new ERR_INVALID_ARG_TYPE('warning', ['Error', 'string'], warning);
-    }
-    if (warning.name === 'DeprecationWarning') {
-      if (process.noDeprecation)
-        return;
-      if (process.throwDeprecation)
-        throw warning;
-    }
-    if (now) process.emit('warning', warning);
-    else process.nextTick(doEmitWarning(warning));
-  };
+// process.emitWarning(error)
+// process.emitWarning(str[, type[, code]][, ctor])
+// process.emitWarning(str[, options])
+function emitWarning(warning, type, code, ctor, now) {
+  let detail;
+  if (type !== null && typeof type === 'object' && !Array.isArray(type)) {
+    ctor = type.ctor;
+    code = type.code;
+    if (typeof type.detail === 'string')
+      detail = type.detail;
+    type = type.type || 'Warning';
+  } else if (typeof type === 'function') {
+    ctor = type;
+    code = undefined;
+    type = 'Warning';
+  }
+  if (type !== undefined && typeof type !== 'string') {
+    throw new ERR_INVALID_ARG_TYPE('type', 'string', type);
+  }
+  if (typeof code === 'function') {
+    ctor = code;
+    code = undefined;
+  } else if (code !== undefined && typeof code !== 'string') {
+    throw new ERR_INVALID_ARG_TYPE('code', 'string', code);
+  }
+  if (typeof warning === 'string') {
+    // Improve error creation performance by skipping the error frames.
+    // They are added in the `captureStackTrace()` function below.
+    const tmpStackLimit = Error.stackTraceLimit;
+    Error.stackTraceLimit = 0;
+    // eslint-disable-next-line no-restricted-syntax
+    warning = new Error(warning);
+    Error.stackTraceLimit = tmpStackLimit;
+    warning.name = String(type || 'Warning');
+    if (code !== undefined) warning.code = code;
+    if (detail !== undefined) warning.detail = detail;
+    Error.captureStackTrace(warning, ctor || process.emitWarning);
+  } else if (!(warning instanceof Error)) {
+    throw new ERR_INVALID_ARG_TYPE('warning', ['Error', 'string'], warning);
+  }
+  if (warning.name === 'DeprecationWarning') {
+    if (process.noDeprecation)
+      return;
+    if (process.throwDeprecation)
+      throw warning;
+  }
+  if (now) process.emit('warning', warning);
+  else process.nextTick(doEmitWarning(warning));
 }
+
+module.exports = {
+  onWarning,
+  emitWarning
+};