fix(44837): add graceful recovery for require completions (microsoft#45151)

Author: a-tarasyuk

src/services/stringCompletions.ts

@@ -184,14 +184,14 @@ namespace ts.Completions.StringCompletions {
 
             case SyntaxKind.CallExpression:
             case SyntaxKind.NewExpression:
-                if (!isRequireCall(parent, /*checkArgumentIsStringLiteralLike*/ false) && !isImportCall(parent)) {
+                if (!isRequireCallArgument(node) && !isImportCall(parent)) {
                     const argumentInfo = SignatureHelp.getArgumentInfoForCompletions(node, position, sourceFile);
                     // Get string literal completions from specialized signatures of the target
                     // i.e. declare function f(a: 'A');
                     // f("/*completion position*/")
                     return argumentInfo ? getStringLiteralCompletionsFromSignature(argumentInfo, typeChecker) : fromContextualType();
                 }
-                // falls through (is `require("")` or `import("")`)
+                // falls through (is `require("")` or `require(""` or `import("")`)
 
             case SyntaxKind.ImportDeclaration:
             case SyntaxKind.ExportDeclaration:
@@ -759,4 +759,14 @@ namespace ts.Completions.StringCompletions {
     function containsSlash(fragment: string) {
         return stringContains(fragment, directorySeparator);
     }
+
+    /**
+     * Matches
+     *   require(""
+     *   require("")
+     */
+    function isRequireCallArgument(node: Node) {
+        return isCallExpression(node.parent) && firstOrUndefined(node.parent.arguments) === node
+            && isIdentifier(node.parent.expression) && node.parent.expression.escapedText === "require";
+    }
 }

tests/cases/fourslash/completionsInRequire.ts

@@ -0,0 +1,25 @@
+/// <reference path='fourslash.ts' />
+
+// @allowJs: true
+// @Filename: foo.js
+////var foo = require("/**/"
+////
+////foo();
+////
+/////**
+//// * @return {void}
+//// */
+////function foo() {
+////}
+
+// @Filename: package.json
+//// { "dependencies": { "fake-module": "latest" } }
+
+// @Filename: node_modules/fake-module/index.js
+/////* fake-module */
+
+verify.completions({
+    marker: "",
+    exact: ["fake-module"],
+    isNewIdentifierLocation: true
+})