Handle CommonJS exports

When we export a class or function expression (as opposed to class or
function definition), the exported symbol should be used as the
canonical definition.

Author: nicolas-guichard

snapshots/output/pure-js/src/exports.js

@@ -1,34 +1,28 @@
 // < definition pure-js 1.0.0 src/`exports.js`/
 
 exports.SomeExportedClass = class LocalClassName {
-//^^^^^ reference local 1
-//      ^^^^^^^^^^^^^^^^^ definition local 2
-//                                ^^^^^^^^^^^^^^ reference local 1
+//      ^^^^^^^^^^^^^^^^^ definition pure-js 1.0.0 src/`exports.js`/exports.SomeExportedClass#
+//                                ^^^^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.SomeExportedClass#
   method() {}
-//^^^^^^ definition local 4
+//^^^^^^ definition pure-js 1.0.0 src/`exports.js`/exports.SomeExportedClass#method().
 }
 
 module.exports.SomeAnonymousClass = class /*anonymous*/ {
-//^^^^ reference local 6
-//     ^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/
-//             ^^^^^^^^^^^^^^^^^^ definition local 8
+//^^^^ reference local 1
+//             ^^^^^^^^^^^^^^^^^^ definition pure-js 1.0.0 src/`exports.js`/exports.SomeAnonymousClass#
   method() {}
-//^^^^^^ definition local 11
+//^^^^^^ definition pure-js 1.0.0 src/`exports.js`/exports.SomeAnonymousClass#method().
 }
 
 exports.someFunc = function localFuncName() {}
-//^^^^^ reference local 14
-//      ^^^^^^^^ definition local 15
-//                          ^^^^^^^^^^^^^ reference local 16
+//      ^^^^^^^^ definition pure-js 1.0.0 src/`exports.js`/exports.someFunc.
+//                          ^^^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.someFunc.
 exports.someAnonymousFunc = function () /*anonymous*/ {}
-//^^^^^ reference local 19
-//      ^^^^^^^^^^^^^^^^^ definition local 20
+//      ^^^^^^^^^^^^^^^^^ definition pure-js 1.0.0 src/`exports.js`/exports.someAnonymousFunc.
 
 exports.someArrowFunc = () => {}
-//^^^^^ reference local 23
-//      ^^^^^^^^^^^^^ definition local 24
+//      ^^^^^^^^^^^^^ definition pure-js 1.0.0 src/`exports.js`/exports.someArrowFunc.
 
 exports.someValue = 4
-//^^^^^ reference local 27
-//      ^^^^^^^^^ definition local 28
+//      ^^^^^^^^^ definition pure-js 1.0.0 src/`exports.js`/exports.someValue.
 

snapshots/output/pure-js/src/main.js

@@ -129,33 +129,33 @@ new SomeClass().someMethod2()
 
 import {
   SomeExportedClass,
-//^^^^^^^^^^^^^^^^^ reference local 8
+//^^^^^^^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.SomeExportedClass#
   SomeAnonymousClass,
-//^^^^^^^^^^^^^^^^^^ reference local 10
+//^^^^^^^^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.SomeAnonymousClass#
   someFunc,
-//^^^^^^^^ reference local 13
+//^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.someFunc.
   someAnonymousFunc,
-//^^^^^^^^^^^^^^^^^ reference local 16
+//^^^^^^^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.someAnonymousFunc.
   someArrowFunc,
-//^^^^^^^^^^^^^ reference local 19
+//^^^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.someArrowFunc.
   someValue,
-//^^^^^^^^^ reference local 22
+//^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.someValue.
 } from './exports'
 //     ^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/
 
 new SomeExportedClass().method()
-//  ^^^^^^^^^^^^^^^^^ reference local 8
-//                      ^^^^^^ reference local 24
+//  ^^^^^^^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.SomeExportedClass#
+//                      ^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.SomeExportedClass#method().
 new SomeAnonymousClass().method()
-//  ^^^^^^^^^^^^^^^^^^ reference local 10
-//                       ^^^^^^ reference local 28
+//  ^^^^^^^^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.SomeAnonymousClass#
+//                       ^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.SomeAnonymousClass#method().
 someFunc()
-//^^^^^^ reference local 29
+//^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.someFunc.
 someAnonymousFunc()
-//^^^^^^^^^^^^^^^ reference local 30
+//^^^^^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.someAnonymousFunc.
 someArrowFunc()
-//^^^^^^^^^^^ reference local 31
+//^^^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.someArrowFunc.
 const i = someValue
 //    ^ definition pure-js 1.0.0 src/`main.js`/i.
-//        ^^^^^^^^^ reference local 32
+//        ^^^^^^^^^ reference pure-js 1.0.0 src/`exports.js`/exports.someValue.
 

snapshots/output/syntax/src/decorators.ts

@@ -9,7 +9,7 @@ function MyDecorator(value: Configuration) {
 //                   ^^^^^ definition syntax 1.0.0 src/`decorators.ts`/MyDecorator().(value)
 //                          ^^^^^^^^^^^^^ reference syntax 1.0.0 src/`reusable-types.ts`/Configuration#
   return function (target: Function) {
-//                 ^^^^^^ definition local 2
+//                 ^^^^^^ definition local 1
 //                         ^^^^^^^^ reference typescript 5.9.3 lib/`lib.es5.d.ts`/Function#
 //                         ^^^^^^^^ reference typescript 5.9.3 lib/`lib.es5.d.ts`/Function.
 //                         ^^^^^^^^ reference typescript 5.9.3 lib/`lib.es2015.core.d.ts`/Function#

src/FileIndexer.ts

@@ -115,6 +115,13 @@ export class FileIndexer {
   //
   // This code is directly based off src/services/goToDefinition.ts.
   private getTSSymbolAtLocation(node: ts.Node): ts.Symbol | undefined {
+    // Surprisingly, in `exports.exported = …`, `getSymbolAtLocation` resolves `export` to the assigned symbol.
+    // More surprisingly, in `moduile.exports.exported`, `getSymbolAtLocation` resolves `export` to the file symbol.
+    // Let's just ignore that case.
+    if (isCommonJsExports(node)) {
+      return undefined
+    }
+
     const symbol = this.checker.getSymbolAtLocation(node)
 
     // If this is an alias, and the request came at the declaration location
@@ -445,6 +452,35 @@ export class FileIndexer {
       return fromCache
     }
 
+    if (isCommonJsExports(node)) {
+      return this.cached(
+        node,
+        ScipSymbol.global(
+          this.scipSymbol(node.getSourceFile()),
+          termDescriptor('exports')
+        )
+      )
+    }
+
+    // When we have one of:
+    // ```
+    // obj.prop = class LocalClassName {}
+    // obj.prop = class {}
+    // obj.prop = function localFunctionName() {}
+    // obj.prop = function () {}
+    // ```
+    // use the SCIP symbol from prop for the class or symbol expression.
+    if (ts.isClassExpression(node) || ts.isFunctionExpression(node)) {
+      if (
+        ts.isBinaryExpression(node.parent) &&
+        node.parent.operatorToken.kind === ts.SyntaxKind.FirstAssignment
+      ) {
+        return this.scipSymbol(node.parent.left)
+      }
+
+      return this.newLocalSymbol(node)
+    }
+
     const tsSymbol = this.getTSSymbolAtLocation(node)
     if (
       tsSymbol?.valueDeclaration &&
@@ -971,3 +1007,30 @@ function declarationName(node: ts.Node): ts.Node | undefined {
 function isDefinition(node: ts.Node): boolean {
   return declarationName(node.parent) === node
 }
+
+function isLeftMostOfAPropertyAccess(node: ts.Node): boolean {
+  let parent: ts.Node = node
+  while (ts.isPropertyAccessExpression(parent.parent)) {
+    if (parent.parent.expression !== parent) {
+      return false
+    }
+    parent = parent.parent
+  }
+
+  return true
+}
+
+function isCommonJsExports(node: ts.Node): boolean {
+  if (ts.isPropertyAccessExpression(node)) {
+    return node.getText() === 'module.exports'
+  }
+
+  if (ts.isIdentifier(node)) {
+    return (
+      node.getText() === 'exports' &&
+      (isLeftMostOfAPropertyAccess(node) || isCommonJsExports(node.parent))
+    )
+  }
+
+  return false
+}