support on-demand parse for typedef-shadowed files (#237)

src/files/BrsFile.spec.ts

@@ -2134,18 +2134,19 @@ describe('BrsFile', () => {
 
     describe('type definitions', () => {
         it('only exposes defined functions even if source has more', async () => {
-            await program.addOrReplaceFile('source/main.d.bs', `
+            //parse the .brs file first so it doesn't know about the typedef
+            await program.addOrReplaceFile<BrsFile>('source/main.brs', `
                 sub main()
                 end sub
+                sub speak()
+                end sub
             `);
 
-            const file = await program.addOrReplaceFile<BrsFile>('source/main.brs', `
+            await program.addOrReplaceFile('source/main.d.bs', `
                 sub main()
                 end sub
-                sub speak()
-                end sub
             `);
-            expect(file.parser.references.functionStatements).to.be.empty;
+
             const sourceScope = program.getScopeByName('source');
             const functionNames = sourceScope.getAllCallables().map(x => x.callable.name);
             expect(functionNames).to.include('main');
@@ -2429,6 +2430,46 @@ describe('BrsFile', () => {
         });
     });
 
+    describe('parser getter', () => {
+        it('recreates the parser when missing', async () => {
+            const file = await program.addOrReplaceFile<BrsFile>('source/main.brs', `
+                sub main()
+                end sub
+            `);
+            const parser = file['_parser'];
+            //clear the private _parser instance
+            file['_parser'] = undefined;
+
+            //force the file to get a new instance of parser
+            const newParser = file.parser;
+
+            expect(newParser).to.exist.and.to.not.equal(parser);
+
+            //reference shouldn't change in subsequent accesses
+            expect(file.parser).to.equal(newParser);
+        });
+
+        it('call parse when previously skipped', async () => {
+            await program.addOrReplaceFile<BrsFile>('source/main.d.bs', `
+                sub main()
+                end sub
+            `);
+            const file = await program.addOrReplaceFile<BrsFile>('source/main.brs', `
+                sub main()
+                end sub
+            `);
+            //no functions should be found since the parser was skipped
+            expect(file['_parser']).to.not.exist;
+
+            const stub = sinon.stub(file, 'parse').callThrough();
+
+            //`file.parser` is a getter, so that should force the parse to occur
+            expect(file.parser.references.functionStatements).to.be.lengthOf(1);
+            expect(stub.called).to.be.true;
+            //parse should have been called
+        });
+    });
+
     describe('Plugins', () => {
         it('can load a plugin which transforms the AST', async () => {
             program.plugins = new PluginInterface(

src/files/BrsFile.ts

@@ -138,7 +138,23 @@ export class BrsFile {
         }
     }
 
-    public parser = new Parser();
+    public get parser() {
+        if (!this._parser) {
+            //remove the typedef file (if it exists)
+            this.hasTypedef = false;
+            this.typedefFile = undefined;
+
+            //reset the deferred
+            this.parseDeferred = new Deferred();
+            //parse the file (it should parse fully since there's no linked typedef
+            this.parse(this.fileContents);
+
+            //re-link the typedef (if it exists...which it should)
+            this.resolveTypdef();
+        }
+        return this._parser;
+    }
+    private _parser: Parser;
 
     public fileContents: string;
 
@@ -188,13 +204,6 @@ export class BrsFile {
         //event that fires anytime a dependency changes
         this.unsubscribeFromDependencyGraph = this.program.dependencyGraph.onchange(this.dependencyGraphKey, () => {
             this.resolveTypdef();
-
-            //if there is no typedef file, and this file hasn't been parsed yet, parse it now
-            //(solves issue when typedef gets deleted and this file had skipped parsing)
-            if (!this.hasTypedef && this.wasParseSkipped) {
-                this.parseDeferred = new Deferred();
-                this.parse(this.fileContents);
-            }
         });
 
         const dependencies = this.ownScriptImports.filter(x => !!x.pkgPath).map(x => x.pkgPath.toLowerCase());
@@ -208,11 +217,6 @@ export class BrsFile {
         dependencyGraph.addOrReplace(this.dependencyGraphKey, dependencies);
     }
 
-    /**
-     * Was parsing skipped because the file has a typedef?
-     */
-    private wasParseSkipped = false;
-
     /**
      * Calculate the AST for this file
      * @param fileContents
@@ -226,7 +230,6 @@ export class BrsFile {
 
             //if we have a typedef file, skip parsing this file
             if (this.hasTypedef) {
-                this.wasParseSkipped = true;
                 this.parseDeferred.resolve();
                 return;
             }
@@ -260,7 +263,7 @@ export class BrsFile {
             let tokens = preprocessor.processedTokens.length > 0 ? preprocessor.processedTokens : lexer.tokens;
 
             this.program.logger.time(LogLevel.debug, ['parser.parse', chalk.green(this.pathAbsolute)], () => {
-                this.parser.parse(tokens, {
+                this._parser = Parser.parse(tokens, {
                     mode: this.parseMode,
                     logger: this.program.logger
                 });
@@ -270,7 +273,7 @@ export class BrsFile {
             this.diagnostics.push(
                 ...lexer.diagnostics as BsDiagnostic[],
                 ...preprocessor.diagnostics as BsDiagnostic[],
-                ...this.parser.diagnostics as BsDiagnostic[]
+                ...this._parser.diagnostics as BsDiagnostic[]
             );
 
             //notify AST ready
@@ -289,14 +292,13 @@ export class BrsFile {
                 diagnostic.file = this;
             }
         } catch (e) {
-            this.parser = new Parser();
+            this._parser = new Parser();
             this.diagnostics.push({
                 file: this,
                 range: util.createRange(0, 0, 0, Number.MAX_VALUE),
                 ...DiagnosticMessages.genericParserMessage('Critical error parsing file: ' + JSON.stringify(serializeError(e)))
             });
         }
-        this.wasParseSkipped = false;
         this.parseDeferred.resolve();
     }
 
@@ -318,8 +320,8 @@ export class BrsFile {
         }
 
         let statements = [
-            ...this.parser.references.libraryStatements,
-            ...this.parser.references.importStatements
+            ...this._parser.references.libraryStatements,
+            ...this._parser.references.importStatements
         ];
         for (let result of statements) {
             //register import statements
@@ -652,7 +654,7 @@ export class BrsFile {
     private findFunctionCalls() {
         this.functionCalls = [];
         //for every function in the file
-        for (let func of this.parser.references.functionExpressions) {
+        for (let func of this._parser.references.functionExpressions) {
             //for all function calls in this function
             for (let expression of func.callExpressions) {
 
@@ -891,8 +893,9 @@ export class BrsFile {
 
         //consume tokens backwards until we find someting other than a dot or an identifier
         let tokens = [];
-        for (let i = this.parser.tokens.indexOf(currentToken); i >= 0; i--) {
-            currentToken = this.parser.tokens[i];
+        const parser = this.parser;
+        for (let i = parser.tokens.indexOf(currentToken); i >= 0; i--) {
+            currentToken = parser.tokens[i];
             if (identifierAndDotKinds.includes(currentToken.kind)) {
                 tokens.unshift(currentToken.text);
             } else {
@@ -932,8 +935,9 @@ export class BrsFile {
     }
 
     public getPreviousToken(token: Token) {
-        let idx = this.parser.tokens.indexOf(token);
-        return this.parser.tokens[idx - 1];
+        const parser = this.parser;
+        let idx = parser.tokens.indexOf(token);
+        return parser.tokens[idx - 1];
     }
 
     /**
@@ -1093,7 +1097,7 @@ export class BrsFile {
     }
 
     public dispose() {
-        this.parser?.dispose();
+        this._parser?.dispose();
     }
 }
 

src/globalCallables.ts

@@ -10,12 +10,10 @@ import { InterfaceType } from './types/InterfaceType';
 import { ObjectType } from './types/ObjectType';
 import { StringType } from './types/StringType';
 import { VoidType } from './types/VoidType';
-import { Parser } from './parser';
 import util from './util';
 
 export let globalFile = new BrsFile('global', 'global', null);
-globalFile.parser = new Parser();
-globalFile.parser.parse([]);
+globalFile.parse('');
 
 let mathFunctions = [{
     name: 'Abs',