fix: autocomplete supports adding extensions

core/deno_normalize_import_statement.test.ts

@@ -60,4 +60,19 @@ test("core / deno_normalize_import_statement", () => {
       `import { example } from "https://example.com/foo/bar.ts";`
     )
   ).toEqual(`import { example } from "https://example.com/foo/bar.ts";`);
+
+  expect(
+    normalizeImportStatement(__filename, `import { example } from "./deno";`)
+  ).toEqual(`import { example } from "./deno.ts";`);
+
+  expect(
+    normalizeImportStatement(
+      __filename,
+      `import { example } from "./testdata/file_walker/a";`
+    )
+  ).toEqual(`import { example } from "./testdata/file_walker/a.js";`);
+
+  expect(
+    normalizeImportStatement(__filename, `import { example } from "./none";`)
+  ).toEqual(`import { example } from "./none";`);
 });

core/deno_normalize_import_statement.ts

@@ -2,13 +2,17 @@ import * as path from "path";
 
 import { getDenoDepsDir } from "./deno";
 import { CacheModule } from "./deno_cache";
-import { normalizeFilepath } from "./util";
+import { normalizeFilepath, findNonExtensionModule } from "./util";
 import { Logger } from "./logger";
 
 /**
  * Normalize import statement
- * @param importStatement eg. `import { path } from "../../../../Library/Caches/deno/deps/https/example.com/da88efaa8b70cda7903ddc29b8d4c6ea3015de65329ea393289f4104ae2da941"`
- * @returns string eg. `https://example.com/demo/sub/mod.ts`
+ * eg. `import { path } from "../../../../Library/Caches/deno/deps/https/example.com/da88efaa8b70cda7903ddc29b8d4c6ea3015de65329ea393289f4104ae2da941"`
+ * eg. `import { foo } from "./bar"`
+ * @param importStatement
+ * eg. `import { path } from "https://example.com/demo/sub/mod.ts"`
+ * eg. `import { foo } from "./bar.ts"`
+ * @returns string
  */
 export function normalizeImportStatement(
   filename: string,
@@ -31,26 +35,28 @@ export function normalizeImportStatement(
         ? moduleFilepath
         : path.resolve(path.dirname(filename), moduleFilepath)
     );
-    const rest = matcher[3];
+    const rest = matcher[3] || "";
 
     /* istanbul ignore next */
     logger?.info(
       `normalize import \`${importStatement}\` in file \`${filename}\` with module \`${moduleAbsoluteFilepath}\``
     );
 
-    /* istanbul ignore else */
     if (moduleAbsoluteFilepath.startsWith(getDenoDepsDir())) {
       const cache = CacheModule.create(moduleAbsoluteFilepath);
       /* istanbul ignore else */
       if (cache) {
-        importStatement = `import ${importModuleNames} from "${
-          cache.meta.url
-        }"${
-          /* istanbul ignore next */
-          rest ? rest : ""
-        }`;
+        importStatement = `import ${importModuleNames} from "${cache.meta.url}"${rest}`;
       }
     }
+    // if cache not found. then it should be relative path
+    // eg. `import { foo } from "./bar"`
+    else if (moduleName.startsWith(".")) {
+      importStatement = `import ${importModuleNames} from "${findNonExtensionModule(
+        filename,
+        moduleName
+      )}"${rest}`;
+    }
   }
 
   return importStatement;

core/util.test.ts

@@ -7,6 +7,7 @@ import {
   normalizeFilepath,
   isValidDenoDocument,
   isUntitledDocument,
+  findNonExtensionModule,
 } from "./util";
 
 test("core / util / pathExists", async () => {
@@ -72,3 +73,12 @@ test("core / util / isUntitledDocument", () => {
   expect(isUntitledDocument("../bar")).toBe(false);
   expect(isUntitledDocument("untitled: ")).toBe(true);
 });
+
+test("core / util / findNonExtensionModule", () => {
+  expect(findNonExtensionModule(__filename, "./deno")).toBe("./deno.ts");
+  expect(findNonExtensionModule(__filename, "./logger")).toBe("./logger.ts");
+  expect(findNonExtensionModule(__filename, "./testdata/file_walker/a")).toBe(
+    "./testdata/file_walker/a.js"
+  );
+  expect(findNonExtensionModule(__filename, "./none")).toBe("./none");
+});

core/util.ts

@@ -1,6 +1,6 @@
 import { promises as fs, statSync } from "fs";
 import crypto from "crypto";
-import * as path from "path";
+import path from "path";
 
 export function pathExistsSync(filepath: string): boolean {
   try {
@@ -80,3 +80,44 @@ export function isUntitledDocument(filename: string): boolean {
   // In vscode, tsserver may crash because a temporary document is not saved
   return /^untitled:/.test(filename);
 }
+
+/**
+ * find module which has no extension name
+ * We hope it can find the module correctly in Deno's way
+ * eg. `import { foo } from "./bar"` should be `import { foo } from "./bar.ts"`
+ * @param filepath
+ * @param moduleName
+ */
+export function findNonExtensionModule(
+  filepath: string,
+  moduleName: string
+): string {
+  function resolveModule(modulePath: string): string | void {
+    if (pathExistsSync(path.resolve(path.dirname(filepath), modulePath))) {
+      return modulePath;
+    }
+
+    return;
+  }
+
+  const denoSupportedExtensions = [
+    ".ts",
+    ".tsx",
+    ".d.ts",
+    ".js",
+    ".jsx",
+    ".mjs",
+  ];
+
+  while (denoSupportedExtensions.length) {
+    const extension = denoSupportedExtensions.shift();
+
+    const modulePath = resolveModule(moduleName + extension);
+
+    if (modulePath) {
+      return modulePath;
+    }
+  }
+
+  return moduleName;
+}