Merge pull request #11819 from Microsoft/vladima/11752

treat ambient non-aliased 'require' as commonjs 'require'

src/compiler/checker.ts

@@ -12825,16 +12825,41 @@ namespace ts {
             }
 
             // In JavaScript files, calls to any identifier 'require' are treated as external module imports
-            if (isInJavaScriptFile(node) &&
-                isRequireCall(node, /*checkArgumentIsStringLiteral*/true) &&
-                // Make sure require is not a local function
-                !resolveName(node.expression, (<Identifier>node.expression).text, SymbolFlags.Value, /*nameNotFoundMessage*/ undefined, /*nameArg*/ undefined)) {
+            if (isInJavaScriptFile(node) && isCommonJsRequire(node)) {
                 return resolveExternalModuleTypeByLiteral(<StringLiteral>node.arguments[0]);
             }
 
             return getReturnTypeOfSignature(signature);
         }
 
+        function isCommonJsRequire(node: Node) {
+            if (!isRequireCall(node, /*checkArgumentIsStringLiteral*/true)) {
+                return false;
+            }
+                // Make sure require is not a local function
+            const resolvedRequire = resolveName(node.expression, (<Identifier>node.expression).text, SymbolFlags.Value, /*nameNotFoundMessage*/ undefined, /*nameArg*/ undefined);
+            if (!resolvedRequire) {
+                // project does not contain symbol named 'require' - assume commonjs require
+                return true;
+            }
+            // project includes symbol named 'require' - make sure that it it ambient and local non-alias
+            if (resolvedRequire.flags & SymbolFlags.Alias) {
+                return false;
+            }
+
+            const targetDeclarationKind = resolvedRequire.flags & SymbolFlags.Function
+                ? SyntaxKind.FunctionDeclaration
+                : resolvedRequire.flags & SymbolFlags.Variable
+                    ? SyntaxKind.VariableDeclaration
+                    : SyntaxKind.Unknown;
+            if (targetDeclarationKind !== SyntaxKind.Unknown) {
+                const decl = getDeclarationOfKind(resolvedRequire, targetDeclarationKind);
+                // function/variable declaration should be ambient
+                return isInAmbientContext(decl);
+            }
+            return false;
+        }
+
         function checkTaggedTemplateExpression(node: TaggedTemplateExpression): Type {
             return getReturnTypeOfSignature(getResolvedSignature(node));
         }

tests/baselines/reference/ambientRequireFunction.js

@@ -0,0 +1,21 @@
+//// [tests/cases/compiler/ambientRequireFunction.ts] ////
+
+//// [node.d.ts]
+
+
+declare function require(moduleName: string): any;
+
+declare module "fs" {
+    export function readFileSync(s: string): string;
+}
+
+//// [app.js]
+/// <reference path="node.d.ts"/>
+
+const fs = require("fs");
+const text = fs.readFileSync("/a/b/c");
+
+//// [app.js]
+/// <reference path="node.d.ts"/>
+var fs = require("fs");
+var text = fs.readFileSync("/a/b/c");

tests/baselines/reference/ambientRequireFunction.symbols

@@ -0,0 +1,27 @@
+=== tests/cases/compiler/app.js ===
+/// <reference path="node.d.ts"/>
+
+const fs = require("fs");
+>fs : Symbol(fs, Decl(app.js, 2, 5))
+>require : Symbol(require, Decl(node.d.ts, 0, 0))
+>"fs" : Symbol("fs", Decl(node.d.ts, 2, 50))
+
+const text = fs.readFileSync("/a/b/c");
+>text : Symbol(text, Decl(app.js, 3, 5))
+>fs.readFileSync : Symbol(readFileSync, Decl(node.d.ts, 4, 21))
+>fs : Symbol(fs, Decl(app.js, 2, 5))
+>readFileSync : Symbol(readFileSync, Decl(node.d.ts, 4, 21))
+
+=== tests/cases/compiler/node.d.ts ===
+
+
+declare function require(moduleName: string): any;
+>require : Symbol(require, Decl(node.d.ts, 0, 0))
+>moduleName : Symbol(moduleName, Decl(node.d.ts, 2, 25))
+
+declare module "fs" {
+    export function readFileSync(s: string): string;
+>readFileSync : Symbol(readFileSync, Decl(node.d.ts, 4, 21))
+>s : Symbol(s, Decl(node.d.ts, 5, 33))
+}
+

tests/baselines/reference/ambientRequireFunction.types

@@ -0,0 +1,30 @@
+=== tests/cases/compiler/app.js ===
+/// <reference path="node.d.ts"/>
+
+const fs = require("fs");
+>fs : typeof "fs"
+>require("fs") : typeof "fs"
+>require : (moduleName: string) => any
+>"fs" : "fs"
+
+const text = fs.readFileSync("/a/b/c");
+>text : string
+>fs.readFileSync("/a/b/c") : string
+>fs.readFileSync : (s: string) => string
+>fs : typeof "fs"
+>readFileSync : (s: string) => string
+>"/a/b/c" : "/a/b/c"
+
+=== tests/cases/compiler/node.d.ts ===
+
+
+declare function require(moduleName: string): any;
+>require : (moduleName: string) => any
+>moduleName : string
+
+declare module "fs" {
+    export function readFileSync(s: string): string;
+>readFileSync : (s: string) => string
+>s : string
+}
+

tests/baselines/reference/localRequireFunction.js

@@ -0,0 +1,15 @@
+//// [app.js]
+
+function require(a) {
+    return a;
+}
+
+const fs = require("fs");
+const text = fs.readFileSync("/a/b/c");
+
+//// [app.js]
+function require(a) {
+    return a;
+}
+var fs = require("fs");
+var text = fs.readFileSync("/a/b/c");

tests/baselines/reference/localRequireFunction.symbols

@@ -0,0 +1,18 @@
+=== tests/cases/compiler/app.js ===
+
+function require(a) {
+>require : Symbol(require, Decl(app.js, 0, 0))
+>a : Symbol(a, Decl(app.js, 1, 17))
+
+    return a;
+>a : Symbol(a, Decl(app.js, 1, 17))
+}
+
+const fs = require("fs");
+>fs : Symbol(fs, Decl(app.js, 5, 5))
+>require : Symbol(require, Decl(app.js, 0, 0))
+
+const text = fs.readFileSync("/a/b/c");
+>text : Symbol(text, Decl(app.js, 6, 5))
+>fs : Symbol(fs, Decl(app.js, 5, 5))
+

tests/baselines/reference/localRequireFunction.types

@@ -0,0 +1,24 @@
+=== tests/cases/compiler/app.js ===
+
+function require(a) {
+>require : (a: any) => any
+>a : any
+
+    return a;
+>a : any
+}
+
+const fs = require("fs");
+>fs : any
+>require("fs") : any
+>require : (a: any) => any
+>"fs" : "fs"
+
+const text = fs.readFileSync("/a/b/c");
+>text : any
+>fs.readFileSync("/a/b/c") : any
+>fs.readFileSync : any
+>fs : any
+>readFileSync : any
+>"/a/b/c" : "/a/b/c"
+

tests/cases/compiler/ambientRequireFunction.ts

@@ -0,0 +1,17 @@
+// @module: commonjs
+// @allowJs: true
+// @outDir: ./out/
+
+// @filename: node.d.ts
+
+declare function require(moduleName: string): any;
+
+declare module "fs" {
+    export function readFileSync(s: string): string;
+}
+
+// @filename: app.js
+/// <reference path="node.d.ts"/>
+
+const fs = require("fs");
+const text = fs.readFileSync("/a/b/c");

tests/cases/compiler/localRequireFunction.ts

@@ -0,0 +1,11 @@
+// @module: commonjs
+// @allowJs: true
+// @outDir: ./out/
+
+// @filename: app.js
+function require(a) {
+    return a;
+}
+
+const fs = require("fs");
+const text = fs.readFileSync("/a/b/c");