Missing Option Explicit diagnostic

Author: SSlinky

server/src/capabilities/diagnostics.ts

@@ -35,4 +35,12 @@ export class WhileWendDeprecatedDiagnostic extends BaseDiagnostic {
 	constructor(range: Range) {
 		super(range);
 	}
+}
+
+export class MissingOptionExplicitDiagnostic extends BaseDiagnostic {
+	message = "Option Explicit is missing from module header.";
+	severity = DiagnosticSeverity.Warning;
+	constructor(range: Range) {
+		super(range);
+	}
 }

server/src/project/elements/module.ts

@@ -1,15 +1,17 @@
 import { TextDocument } from 'vscode-languageserver-textdocument';
-import { SymbolInformation, SymbolKind } from 'vscode-languageserver';
-import { AttributeStmtContext, ModuleContext } from '../../antlr/out/vbaParser';
+import { Diagnostic, SymbolInformation, SymbolKind } from 'vscode-languageserver';
+import { AttributeStmtContext, ModuleContext, ModuleHeaderContext, ModuleOptionContext } from '../../antlr/out/vbaParser';
 
-import { BaseContextSyntaxElement, HasAttribute, HasSymbolInformation } from './base';
+import { BaseContextSyntaxElement, HasAttribute, HasDiagnosticCapability, HasSymbolInformation } from './base';
 import { SymbolInformationFactory } from '../../capabilities/symbolInformation';
+import { MissingOptionExplicitDiagnostic } from '../../capabilities/diagnostics';
 
 
-export class ModuleElement extends BaseContextSyntaxElement implements HasSymbolInformation, HasAttribute {
+export class ModuleElement extends BaseContextSyntaxElement implements HasSymbolInformation, HasAttribute, HasDiagnosticCapability {
 	private _hasName = false;
 	private _name: string;
 	symbolKind: SymbolKind;
+	diagnostics: Diagnostic[] = [];
 
 	constructor(context: ModuleContext, document: TextDocument, symbolKind: SymbolKind) {
 		super(context, document);
@@ -27,6 +29,32 @@ export class ModuleElement extends BaseContextSyntaxElement implements HasSymbol
 		);
 	}
 
+	evaluateDiagnostics(): void {
+		const optionExplicitDiagnotic = this._getOptionExplicitDiagnostic();
+		if (optionExplicitDiagnotic) {
+			this.diagnostics.push(optionExplicitDiagnotic);
+		}
+	}
+
+	private _getOptionExplicitDiagnostic(): Diagnostic | undefined {
+		let optionExplicitFound = false;
+		const context = this.context as ModuleContext;
+		const declarations = context.moduleHeader().moduleDeclarations()?.moduleDeclarationsElement();
+
+		if (declarations) {
+			for (const declaration of declarations) {
+				if ((declaration.moduleOption()?.text ?? '') === 'Option Explicit') {
+					optionExplicitFound = true;
+					break;
+				}
+			}
+		}
+
+		return optionExplicitFound ? undefined : new MissingOptionExplicitDiagnostic(
+			(new ModuelHeaderElement(context.moduleHeader(), this.document)).range
+		);
+	}
+
 	processAttribute(context: AttributeStmtContext): void {
 		if (this._hasName) {
 			return;
@@ -42,3 +70,9 @@ export class ModuleElement extends BaseContextSyntaxElement implements HasSymbol
 		}
 	}
 }
+
+class ModuelHeaderElement extends BaseContextSyntaxElement {
+	constructor(context: ModuleHeaderContext, document: TextDocument) {
+		super(context, document);
+	}
+}