Throw diagnostic error when main adl file is not found. (#560)

packages/adl/compiler/diagnostics.ts

@@ -32,6 +32,7 @@ export class AggregateError extends Error {
   }
 }
 
+export const NoTarget = Symbol("NoTarget");
 export type DiagnosticTarget = Node | Type | Sym | SourceLocation;
 export type WriteLine = (text?: string) => void;
 
@@ -45,7 +46,7 @@ export const throwOnError: ErrorHandler = throwDiagnostic;
 
 export function throwDiagnostic(
   message: Message | string,
-  target: DiagnosticTarget,
+  target: DiagnosticTarget | typeof NoTarget,
   args?: (string | number)[]
 ): never {
   throw new DiagnosticError([createDiagnostic(message, target, args)]);
@@ -53,17 +54,18 @@ export function throwDiagnostic(
 
 export function createDiagnostic(
   message: Message | string,
-  target: DiagnosticTarget,
+  target: DiagnosticTarget | typeof NoTarget,
   args?: (string | number)[]
 ): Diagnostic {
-  let location: SourceLocation;
+  let location: Partial<SourceLocation> = {};
   let locationError: Error | undefined;
-
-  try {
-    location = getSourceLocation(target);
-  } catch (err) {
-    locationError = err;
-    location = createDummySourceLocation();
+  if (target !== NoTarget) {
+    try {
+      location = getSourceLocation(target);
+    } catch (err) {
+      locationError = err;
+      location = createDummySourceLocation();
+    }
   }
 
   if (typeof message === "string") {
@@ -94,12 +96,17 @@ export function logDiagnostics(diagnostics: readonly Diagnostic[], writeLine: Wr
 
 export function formatDiagnostic(diagnostic: Diagnostic) {
   const code = diagnostic.code ? ` ADL${diagnostic.code}` : "";
-  const pos = diagnostic.file.getLineAndCharacterOfPosition(diagnostic.pos);
-  const line = pos.line + 1;
-  const col = pos.character + 1;
   const severity = diagnostic.severity;
-  const path = diagnostic.file.path;
-  return `${path}:${line}:${col} - ${severity}${code}: ${diagnostic.message}`;
+  const content = `${severity}${code}: ${diagnostic.message}`;
+  if (diagnostic.file) {
+    const pos = diagnostic.file.getLineAndCharacterOfPosition(diagnostic.pos ?? 0);
+    const line = pos.line + 1;
+    const col = pos.character + 1;
+    const path = diagnostic.file.path;
+    return `${path}:${line}:${col} - ${content}`;
+  } else {
+    return content;
+  }
 }
 
 export function createSourceFile(text: string, path: string): SourceFile {

packages/adl/compiler/messages.ts

@@ -59,6 +59,12 @@ export const Message = {
     severity: "error",
     text: "Invalid character.",
   } as const,
+
+  FileNotFound: {
+    code: 1109,
+    text: `File {0} is not found.`,
+    severity: "error",
+  } as const,
 };
 
 // Static assert: this won't compile if one of the entries above is invalid.

packages/adl/compiler/program.ts

@@ -2,7 +2,8 @@ import { dirname, extname, isAbsolute, join, resolve } from "path";
 import resolveModule from "resolve";
 import { createBinder, createSymbolTable } from "./binder.js";
 import { createChecker } from "./checker.js";
-import { createSourceFile, DiagnosticError, throwDiagnostic } from "./diagnostics.js";
+import { createSourceFile, DiagnosticError, NoTarget, throwDiagnostic } from "./diagnostics.js";
+import { Message } from "./messages.js";
 import { CompilerOptions } from "./options.js";
 import { parse } from "./parser.js";
 import {
@@ -349,8 +350,7 @@ export async function createProgram(
 
     const mainPath = resolve(host.getCwd(), options.mainFile);
 
-    const mainStat = await host.stat(mainPath);
-
+    const mainStat = await getMainPathStats(mainPath);
     if (mainStat.isDirectory()) {
       await loadDirectory(mainPath);
     } else {
@@ -358,6 +358,17 @@ export async function createProgram(
     }
   }
 
+  async function getMainPathStats(mainPath: string) {
+    try {
+      return await host.stat(mainPath);
+    } catch (e) {
+      if (e.code === "ENOENT") {
+        throwDiagnostic(Message.FileNotFound, NoTarget, [mainPath]);
+      }
+      throw e;
+    }
+  }
+
   function getOption(key: string): string | undefined {
     return (options.miscOptions || {})[key];
   }

packages/adl/compiler/types.ts

@@ -507,7 +507,7 @@ export interface SourceLocation extends TextRange {
   file: SourceFile;
 }
 
-export interface Diagnostic extends SourceLocation {
+export interface Diagnostic extends Partial<SourceLocation> {
   message: string;
   code?: number;
   severity: "warning" | "error";

packages/adl/formatter/parser.ts

@@ -20,8 +20,8 @@ export class PrettierParserError extends Error {
   public constructor(public readonly error: Diagnostic) {
     super(error.message);
     this.loc = {
-      start: error.pos,
-      end: error.end,
+      start: error.pos ?? 0,
+      end: error.end ?? 0,
     };
   }
 }

packages/adl/server/server.ts

@@ -50,8 +50,8 @@ function checkChange(change: TextDocumentChangeEvent<TextDocument>) {
   const diagnostics: Diagnostic[] = [];
 
   for (const each of parseDiagnostics) {
-    const start = document.positionAt(each.pos);
-    const end = document.positionAt(each.end);
+    const start = document.positionAt(each.pos ?? 0);
+    const end = document.positionAt(each.end ?? 0);
     const range = Range.create(start, end);
     const severity = convertSeverity(each.severity);
     const diagnostic = Diagnostic.create(range, each.message, severity, each.code, "ADL");