Merge pull request #14984 from Microsoft/backtick

Support backticks in require calls

Author: Andy

src/compiler/checker.ts

@@ -1564,7 +1564,7 @@ namespace ts {
         }
 
         function resolveExternalModuleNameWorker(location: Node, moduleReferenceExpression: Expression, moduleNotFoundError: DiagnosticMessage, isForAugmentation = false): Symbol {
-            if (moduleReferenceExpression.kind !== SyntaxKind.StringLiteral) {
+            if (moduleReferenceExpression.kind !== SyntaxKind.StringLiteral && moduleReferenceExpression.kind !== SyntaxKind.NoSubstitutionTemplateLiteral) {
                 return;
             }
 

src/compiler/utilities.ts

@@ -1404,17 +1404,24 @@ namespace ts {
 
     /**
      * Returns true if the node is a CallExpression to the identifier 'require' with
-     * exactly one argument.
+     * exactly one argument (of the form 'require("name")').
      * This function does not test if the node is in a JavaScript file or not.
-    */
-    export function isRequireCall(expression: Node, checkArgumentIsStringLiteral: boolean): expression is CallExpression {
-        // of the form 'require("name")'
-        const isRequire = expression.kind === SyntaxKind.CallExpression &&
-            (<CallExpression>expression).expression.kind === SyntaxKind.Identifier &&
-            (<Identifier>(<CallExpression>expression).expression).text === "require" &&
-            (<CallExpression>expression).arguments.length === 1;
-
-        return isRequire && (!checkArgumentIsStringLiteral || (<CallExpression>expression).arguments[0].kind === SyntaxKind.StringLiteral);
+     */
+    export function isRequireCall(callExpression: Node, checkArgumentIsStringLiteral: boolean): callExpression is CallExpression {
+        if (callExpression.kind !== SyntaxKind.CallExpression) {
+            return false;
+        }
+        const { expression, arguments } = callExpression as CallExpression;
+
+        if (expression.kind !== SyntaxKind.Identifier || (expression as Identifier).text !== "require") {
+            return false;
+        }
+
+        if (arguments.length !== 1) {
+            return false;
+        }
+        const arg = arguments[0];
+        return !checkArgumentIsStringLiteral || arg.kind === SyntaxKind.StringLiteral || arg.kind === SyntaxKind.NoSubstitutionTemplateLiteral;
     }
 
     export function isSingleOrDoubleQuote(charCode: number) {

tests/cases/fourslash/javaScriptModulesWithBackticks.ts

@@ -0,0 +1,12 @@
+///<reference path="fourslash.ts" />
+
+// @allowJs: true
+// @Filename: a.js
+//// exports.x = 0;
+
+// @Filename: consumer.js
+//// var a = require(`./a`);
+//// a./**/;
+
+goTo.marker();
+verify.completionListContains("x");