Avoid "Cannot add name" error for ParamArray and Optional arguments

package.json

@@ -27,7 +27,9 @@
 	},
 	"main": "dist/client/out/extension",
 	"browser": "dist/web/webextension.js",
-	"activationEvents": ["onLanguage:vba"],
+	"activationEvents": [
+		"onLanguage:vba"
+	],
 	"contributes": {
 		"languages": [
 			{
@@ -183,6 +185,7 @@
 		"@vscode/test-electron": "^2.5.2",
 		"@vscode/vsce": "^3.7.1",
 		"antlr4ng-cli": "^2.0.0",
+		"dedent": "^1.7.1",
 		"esbuild": "^0.25.4",
 		"eslint": "^9.27.0",
 		"js-yaml": "^4.1.0",

server/src/project/elements/naming.ts

@@ -9,6 +9,8 @@ import {
     IndexExpressionContext,
     LExpressionContext,
     MemberAccessExpressionContext,
+    OptionalParamContext,
+    ParamArrayContext,
     PositionalParamContext,
     SimpleNameExpressionContext,
     UnrestrictedNameContext,
@@ -37,6 +39,8 @@ export class WithStatementElement extends BaseRuleSyntaxElement<WithStatementCon
 export type NameExpressionContext = LExpressionContext
     | SimpleNameExpressionContext
     | MemberAccessExpressionContext
+    | OptionalParamContext
+    | ParamArrayContext
     | PositionalParamContext
     | IndexExpressionContext
     | WithMemberAccessExpressionContext

server/src/project/parser/vbaListener.ts

@@ -346,6 +346,7 @@ export class VbaListener extends vbaListener {
 
     enterOptionalParam = (ctx: OptionalParamContext) => {
         if (this.verbose) Services.logger.debug(`enterOptionalParam: ${ctx.getText()}`, this.parserStateStack.length);
+        this.pushNameElement(ctx);
         const identifierCtx = ctx.paramDcl().untypedNameParamDcl()?.ambiguousIdentifier()
             ?? ctx.paramDcl().typedNameParamDcl()?.typedName().ambiguousIdentifier();
 
@@ -361,6 +362,7 @@ export class VbaListener extends vbaListener {
 
     enterParamArray = (ctx: ParamArrayContext) => {
         if (this.verbose) Services.logger.debug(`enterParamArray: ${ctx.getText()}`, this.parserStateStack.length);
+        this.pushNameElement(ctx);
         this.addNameElementContext(ctx.ambiguousIdentifier(), 'ambigiousNameContext');
     };
 
@@ -383,6 +385,10 @@ export class VbaListener extends vbaListener {
         nameElement.addName(ctx);
     }
 
+    /**
+     * Creates and pushes the active name-expression container for the current
+     * parse context.
+     */
     private pushNameElement(ctx: NameExpressionContext): void {
         if (this.verbose) Services.logger.debug('Pushing name', this.parserStateStack.length);
         const element = new NameExpressionElement(ctx, this.document.textDocument);

server/src/test/vbaListener.test.ts

@@ -0,0 +1,106 @@
+import 'reflect-metadata';
+import { describe, it } from 'mocha';
+import * as assert from 'assert';
+import dedent from 'dedent';
+import { container } from 'tsyringe';
+import { CancellationTokenSource } from 'vscode-languageserver';
+import { TextDocument } from 'vscode-languageserver-textdocument';
+
+import '../extensions/antlrCoreExtensions';
+import '../extensions/antlrVbaParserExtensions';
+import '../extensions/stringExtensions';
+
+import { ScopeItemCapability, ScopeType } from '../capabilities/capabilities';
+import { BaseProjectDocument } from '../project/document';
+
+type LogNotification = {
+    type: number;
+    message: string;
+    level: number;
+};
+
+const ERROR_LOG_TYPE = 1;
+
+function assertNoErrorLogs(logs: LogNotification[], context: string): void {
+    const errorLogs = logs.filter(log => log.type === ERROR_LOG_TYPE);
+
+    assert.strictEqual(
+        errorLogs.length,
+        0,
+        `${context} produced error logs: ${errorLogs.map(x => x.message).join(' | ')}`
+    );
+}
+
+function registerTestServices(logs: LogNotification[]): void {
+    container.clearInstances();
+
+    container.registerInstance('_Connection', {
+        sendNotification: (_method: string, payload: LogNotification) => logs.push(payload)
+    } as any);
+
+    container.registerInstance('ILanguageServer', {
+        clientConfiguration: Promise.resolve({
+            maxDocumentLines: 50000,
+            maxNumberOfProblems: 100,
+            doWarnOptionExplicitMissing: true,
+            environment: { os: 'test', version: 'test' },
+            logLevel: { outputChannel: 'debug' }
+        })
+    } as any);
+
+    container.registerInstance('IWorkspace', {
+        clearDocumentsConfiguration: () => undefined,
+        formatParseDocument: async () => undefined,
+        parseDocument: async () => undefined,
+        openDocument: () => undefined,
+        closeDocument: () => undefined,
+        addWorkspaceFolder: async () => undefined
+    } as any);
+
+    const languageScope = new ScopeItemCapability(undefined, ScopeType.VBA);
+    const appScope = new ScopeItemCapability(undefined, ScopeType.APPLICATION, undefined, languageScope);
+    const projectScope = new ScopeItemCapability(undefined, ScopeType.PROJECT, undefined, appScope);
+    container.registerInstance('ProjectScope', projectScope);
+}
+
+async function parseText(uri: string, text: string, logs: LogNotification[]): Promise<void> {
+    registerTestServices(logs);
+    const textDocument = TextDocument.create(uri, 'vba', 1, text);
+    const projectDocument = BaseProjectDocument.create(textDocument);
+    await projectDocument.parse(new CancellationTokenSource().token);
+}
+
+describe('VBA Listener Integration', () => {
+    it('does not log optional parameter identifiers as unresolved names', async () => {
+        const logs: LogNotification[] = [];
+        const vbaCode = dedent`
+            Attribute VB_Name = "ScopeDiagnostics"
+
+            Option Explicit
+
+            Public Sub TestSub(Optional test_param As Variant = -0.1)
+            Attribute TestSub.VB_Description = "docstring."
+            End Sub
+        `;
+
+        await parseText('file:///test/ScopeDiagnostics.bas', vbaCode, logs);
+
+        assertNoErrorLogs(logs, 'Optional parameter parse');
+    });
+
+    it('does not log ParamArray identifiers as unresolved names', async () => {
+        const logs: LogNotification[] = [];
+        const vbaCode = dedent`
+            Attribute VB_Name = "ParamArrayTest"
+
+            Option Explicit
+
+            Public Sub TestVariadicSub(ParamArray args() As Variant)
+            End Sub
+        `;
+
+        await parseText('file:///test/ParamArrayTest.bas', vbaCode, logs);
+
+        assertNoErrorLogs(logs, 'ParamArray parse');
+    });
+});