semanticToken request wait until validate finishes

src/LanguageServer.spec.ts

@@ -16,6 +16,7 @@ import { expectZeroDiagnostics, trim } from './testHelpers.spec';
 import { isBrsFile, isLiteralString } from './astUtils/reflection';
 import { createVisitor, WalkMode } from './astUtils/visitors';
 import { tempDir, rootDir } from './testHelpers.spec';
+import { URI } from 'vscode-uri';
 
 const sinon = createSandbox();
 
@@ -1103,6 +1104,56 @@ describe('LanguageServer', () => {
             });
         });
     });
+
+    it('semantic tokens request waits until after validation has finished', async () => {
+        fsExtra.outputFileSync(s`${rootDir}/source/main.bs`, `
+            sub main()
+                print \`hello world\`
+            end sub
+        `);
+        let spaceCount = 0;
+        const getContents = () => {
+            return `
+                namespace sgnode
+                    sub speak(message)
+                        print message
+                    end sub
+
+                    sub sayHello()
+                        sgnode.speak("Hello")${' '.repeat(spaceCount++)}
+                    end sub
+                end namespace
+            `;
+        };
+
+        const uri = URI.file(s`${rootDir}/source/sgnode.bs`).toString();
+
+        fsExtra.outputFileSync(s`${rootDir}/source/sgnode.bs`, getContents());
+        server.run();
+        await server['syncProjects']();
+        expectZeroDiagnostics(server.projects[0].builder.program);
+
+        fsExtra.outputFileSync(s`${rootDir}/source/sgnode.bs`, getContents());
+        const changeWatchedFilesPromise = server['onDidChangeWatchedFiles']({
+            changes: [{
+                type: FileChangeType.Changed,
+                uri: uri
+            }]
+        });
+        const document = {
+            getText: () => getContents(),
+            uri: uri
+        } as TextDocument;
+
+        const semanticTokensPromise = server['onFullSemanticTokens']({
+            textDocument: document
+        });
+        await Promise.all([
+            changeWatchedFilesPromise,
+            semanticTokensPromise
+        ]);
+        expectZeroDiagnostics(server.projects[0].builder.program);
+    });
 });
 
 export function getFileProtocolPath(fullPath: string) {

src/LanguageServer.ts

@@ -1080,7 +1080,7 @@ export class LanguageServer {
             // validate all projects
             await this.validateAllThrottled();
         } catch (e: any) {
-            this.sendCriticalFailure(`Critical error parsing / validating ${filePath}: ${e.message}`);
+            this.sendCriticalFailure(`Critical error parsing/validating ${filePath}: ${e.message}`);
         }
     }
 
@@ -1206,7 +1206,13 @@ export class LanguageServer {
     @AddStackToErrorMessage
     private async onFullSemanticTokens(params: SemanticTokensParams) {
         await this.waitAllProjectFirstRuns();
-        await this.keyedThrottler.onIdleOnce(util.uriToPath(params.textDocument.uri), true);
+        await Promise.all([
+            //wait for the file to settle (in case there are multiple file changes in quick succession
+            this.keyedThrottler.onIdleOnce(util.uriToPath(params.textDocument.uri), true),
+            // wait for the validation to finish before providing semantic tokens. program.validate() populates and then caches AstNode.parent properties.
+            // If we don't wait, then fetching semantic tokens can cause some invalid cache
+            this.validateThrottler.onIdleOnce(false)
+        ]);
 
         const srcPath = util.uriToPath(params.textDocument.uri);
         for (const project of this.projects) {