Add a mode that converts to @embroider/macros

This is intended as a compatibility path for packages (like ember-source) that make heavy use of babel-plugin-debug-macros and want to become valid V2 addons.

A v2 addon can't bring its own custom build pipeline along into apps. If they want to make compile-time decisions, they need to do it through the standardized `@embroider/macros`.

This implementation does the smallest, simplest thing, which is replacing the hard-coded boolean we used to emit with a call to `isDevelopingApp()` from '@embroider/macros`. It relies on the same kind of dead-code elimination that this babel plugin has always relied on.

Author: ef4

fixtures/embroider-macros/assert/expectation7.js

@@ -0,0 +1,5 @@
+import { assert } from '@ember/debug';
+import { isDevelopingApp } from '@embroider/macros';
+
+isDevelopingApp() && !(() => true )() && assert('This is an assertion', (() => true )());
+isDevelopingApp() && !false && assert('This is an assertion 2', false);

fixtures/embroider-macros/assert/sample.js

@@ -0,0 +1,4 @@
+import { assert } from '@ember/debug';
+
+assert('This is an assertion', (() => true )());
+assert('This is an assertion 2', false);

fixtures/embroider-macros/deprecate/expectation7.js

@@ -0,0 +1,10 @@
+import { deprecate } from '@ember/debug';
+import { isDevelopingApp } from '@embroider/macros';
+
+isDevelopingApp() &&
+  !false &&
+  deprecate('This is deprecated', false, {
+    until: '3.0.0',
+    id: 'a-thing',
+    url: 'http://example.com',
+  });

fixtures/embroider-macros/deprecate/sample.js

@@ -0,0 +1,7 @@
+import { deprecate } from '@ember/debug';
+
+deprecate('This is deprecated', false, {
+  until: '3.0.0',
+  id: 'a-thing',
+  url: 'http://example.com'
+})

fixtures/embroider-macros/glimmer-env/expectation7.js

@@ -0,0 +1,5 @@
+import { isDevelopingApp } from '@embroider/macros';
+
+if (isDevelopingApp()) {
+  console.log('stuff');
+}

fixtures/embroider-macros/glimmer-env/sample.js

@@ -0,0 +1,5 @@
+import { DEBUG } from '@glimmer/env';
+
+if (DEBUG) {
+  console.log('stuff');
+}

package.json

@@ -33,6 +33,7 @@
     ]
   },
   "dependencies": {
+    "babel-import-util": "^2.0.2",
     "semver": "^7.6.0"
   },
   "devDependencies": {

pnpm-lock.yaml

@@ -3,10 +3,12 @@ import Macros from './utils/macros';
 import { UserOptions, NormalizedOptions, normalizeOptions } from './utils/normalize-options';
 import * as Babel from '@babel/core';
 import type { types as t } from '@babel/core';
+import { ImportUtil } from 'babel-import-util';
 
 interface State {
   opts: NormalizedOptions;
   macroBuilder: Macros;
+  util: ImportUtil;
 }
 
 export default function macros(babel: typeof Babel): Babel.PluginObj<State> {
@@ -45,7 +47,12 @@ export default function macros(babel: typeof Babel): Babel.PluginObj<State> {
           let binding = path.scope.getBinding(localBindingName)!;
 
           binding.referencePaths.forEach((p) => {
-            p.replaceWith(buildIdentifier(flagValue, flagName));
+            if (flagValue === '@embroider/macros') {
+              p.replaceWith(t.callExpression(state.util.import(p, "@embroider/macros", "isDevelopingApp"), []))
+              p.scope.crawl();
+            } else {
+              p.replaceWith(buildIdentifier(flagValue, flagName));
+            }
           });
 
           path.remove();
@@ -70,7 +77,8 @@ export default function macros(babel: typeof Babel): Babel.PluginObj<State> {
           // most of our plugin declares state.opts as already being normalized.
           // This is the spot where we force it become so.
           state.opts = normalizeOptions(state.opts as unknown as UserOptions);
-          this.macroBuilder = new Macros(babel, state.opts);
+          state.util = new ImportUtil(t, path)
+          this.macroBuilder = new Macros(babel, state.opts, state.util);
 
           let body = path.get('body');
 

src/index.ts

@@ -1,13 +1,13 @@
 import type * as Babel from '@babel/core';
-import type { types as t } from '@babel/core';
-import type { NodePath } from '@babel/core';
+import type { NodePath, types as t } from '@babel/core';
 import { CallIdentifierExpression, CallStatementPath } from './babel-type-helpers';
+import { ImportUtil } from 'babel-import-util';
 
 export interface Options {
   module: boolean | undefined;
   global: string | undefined;
   assertPredicateIndex: number | undefined;
-  isDebug: boolean;
+  isDebug: boolean | "@embroider/macros";
 }
 
 interface MacroExpressionOpts {
@@ -27,18 +27,21 @@ export default class Builder {
   private module: boolean | undefined;
   private global: string | undefined;
   private assertPredicateIndex: number | undefined;
-  private isDebug: boolean;
+  private isDebug: boolean | '@embroider/macros';
+  private util: ImportUtil;
 
   private expressions: [CallStatementPath, (debugIdentifier: t.Expression) => t.Expression][] = [];
 
   constructor(
     readonly t: typeof Babel.types,
+    util: ImportUtil,
     options: Options
   ) {
     this.module = options.module;
     this.global = options.global;
     this.assertPredicateIndex = options.assertPredicateIndex;
     this.isDebug = options.isDebug;
+    this.util = util;
   }
 
   /**
@@ -212,12 +215,24 @@ export default class Builder {
    */
   expandMacros() {
     let t = this.t;
-    let flag = t.booleanLiteral(this.isDebug);
     for (let i = 0; i < this.expressions.length; i++) {
       let expression = this.expressions[i];
       let exp = expression[0];
+      let flag = this._debugExpression(exp);
       let logicalExp = expression[1];
       exp.replaceWith(t.parenthesizedExpression(logicalExp(flag)));
+      exp.scope.crawl();
+    }
+  }
+
+  _debugExpression(target: NodePath) {
+    if (typeof this.isDebug === 'boolean') {
+      return this.t.booleanLiteral(this.isDebug);
+    } else {
+      return this.t.callExpression(
+        this.util.import(target, '@embroider/macros', 'isDevelopingApp'),
+        []
+      );
     }
   }