fix: instantiate Checker once

Author: sam

src/index.ts

@@ -25,23 +25,21 @@ function init(modules: { typescript: typeof tsserver }): any {
       proxy[k] = (...args: Array<{}>) => x.apply(info.languageService, args);
     }
 
+    const program = info.languageService.getProgram();
+    if (program === undefined) {
+      return proxy;
+    }
+
+    const checker = makeFunctionlessChecker(program.getTypeChecker());
+
     proxy.getSemanticDiagnostics = (fileName): ts.Diagnostic[] => {
       const errors = info.languageService.getSemanticDiagnostics(fileName);
-      const program = info.languageService.getProgram();
-      if (program) {
-        const checker = makeFunctionlessChecker(program.getTypeChecker());
-        const sf = program.getSourceFile(fileName);
-
-        if (sf) {
-          info.project.projectService.logger.info(
-            `Calling validate on file: ${fileName}`
-          );
-          const customErrors = validate(ts as any, checker, sf);
-          info.project.projectService.logger.info(
-            `Detected ${customErrors.length} custom errors in file: ${fileName}`
-          );
-          return [...errors, ...customErrors];
-        }
+
+      const sf = program.getSourceFile(fileName);
+
+      if (sf) {
+        const customErrors = validate(ts as any, checker, sf);
+        return [...errors, ...customErrors];
       }
 
       return errors;