From 57e89f2e129f8455fe0968aec58b93ee00dbba00 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 24 Feb 2026 20:18:17 +0000
Subject: [PATCH 1/3] Initial plan


From 8af7d3b51eb8caaa362a795b5968bdee7efe136a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 24 Feb 2026 20:24:47 +0000
Subject: [PATCH 2/3] Extract replLikeEval/checkSyntax into packages/jsEval
 workspace with tests

Co-authored-by: na-trium-144 <100704180+na-trium-144@users.noreply.github.com>
---
 .github/workflows/node.js.yml        |  14 ++
 app/terminal/worker/jsEval.worker.ts |  62 +-------
 package-lock.json                    |  16 +++
 package.json                         |   3 +
 packages/jsEval/package.json         |  16 +++
 packages/jsEval/src/index.test.ts    | 205 +++++++++++++++++++++++++++
 packages/jsEval/src/index.ts         |  65 +++++++++
 packages/jsEval/tsconfig.json        |  11 ++
 8 files changed, 331 insertions(+), 61 deletions(-)
 create mode 100644 packages/jsEval/package.json
 create mode 100644 packages/jsEval/src/index.test.ts
 create mode 100644 packages/jsEval/src/index.ts
 create mode 100644 packages/jsEval/tsconfig.json

diff --git a/.github/workflows/node.js.yml b/.github/workflows/node.js.yml
index caa07b8e..b68ddafa 100644
--- a/.github/workflows/node.js.yml
+++ b/.github/workflows/node.js.yml
@@ -32,3 +32,17 @@ jobs:
         cache: 'npm'
     - run: npm ci
     - run: npm run tsc
+
+  test-js-eval:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node-version: [22.x]
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-node@v4
+      with:
+        node-version: ${{ matrix.node-version }}
+        cache: 'npm'
+    - run: npm ci
+    - run: npm test --workspace=packages/jsEval
diff --git a/app/terminal/worker/jsEval.worker.ts b/app/terminal/worker/jsEval.worker.ts
index 2f777ea9..712a8b8b 100644
--- a/app/terminal/worker/jsEval.worker.ts
+++ b/app/terminal/worker/jsEval.worker.ts
@@ -4,6 +4,7 @@ import { expose } from "comlink";
 import type { ReplOutput } from "../repl";
 import type { WorkerCapabilities } from "./runtime";
 import inspect from "object-inspect";
+import { replLikeEval, checkSyntax } from "@my-code/js-eval";
 
 function format(...args: unknown[]): string {
   // TODO: console.logの第1引数はフォーマット指定文字列を取ることができる
@@ -34,41 +35,6 @@ async function init(/*_interruptBuffer?: Uint8Array*/): Promise<{
   return { capabilities: { interrupt: "restart" } };
 }
 
-async function replLikeEval(code: string): Promise<unknown> {
-  // eval()の中でconst,letを使って変数を作成した場合、
-  // 次に実行するコマンドはスコープ外扱いでありアクセスできなくなってしまうので、
-  // varに置き換えている
-  if (code.trim().startsWith("const ")) {
-    code = "var " + code.trim().slice(6);
-  } else if (code.trim().startsWith("let ")) {
-    code = "var " + code.trim().slice(4);
-  }
-  // eval()の中でclassを作成した場合も同様
-  const classRegExp = /^\s*class\s+(\w+)/;
-  if (classRegExp.test(code)) {
-    code = code.replace(classRegExp, "var $1 = class $1");
-  }
-
-  if (code.trim().startsWith("{") && code.trim().endsWith("}")) {
-    // オブジェクトは ( ) で囲わなければならない
-    try {
-      return self.eval(`(${code})`);
-    } catch (e) {
-      if (e instanceof SyntaxError) {
-        // オブジェクトではなくブロックだった場合、再度普通に実行
-        return self.eval(code);
-      } else {
-        throw e;
-      }
-    }
-  } else if (/^\s*await\W/.test(code)) {
-    // promiseをawaitする場合は、promiseの部分だけをevalし、それを外からawaitする
-    return await self.eval(code.trim().slice(5));
-  } else {
-    return self.eval(code);
-  }
-}
-
 async function runCode(
   code: string,
   onOutput: (output: ReplOutput) => void
@@ -129,32 +95,6 @@ function runFile(
   return { updatedFiles: {} as Record<string, string> };
 }
 
-async function checkSyntax(
-  code: string
-): Promise<{ status: "complete" | "incomplete" | "invalid" }> {
-  try {
-    // Try to create a Function to check syntax
-    // new Function(code); // <- not working
-    self.eval(`() => {${code}}`);
-    return { status: "complete" };
-  } catch (e) {
-    // Check if it's a syntax error or if more input is expected
-    if (e instanceof SyntaxError) {
-      // Simple heuristic: check for "Unexpected end of input"
-      if (
-        e.message.includes("Unexpected token '}'") ||
-        e.message.includes("Unexpected end of input")
-      ) {
-        return { status: "incomplete" };
-      } else {
-        return { status: "invalid" };
-      }
-    } else {
-      return { status: "invalid" };
-    }
-  }
-}
-
 async function restoreState(commands: string[]): Promise<object> {
   // Re-execute all previously successful commands to restore state
   for (const command of commands) {
diff --git a/package-lock.json b/package-lock.json
index a02abb5e..74830297 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -7,6 +7,9 @@
     "": {
       "name": "my-code",
       "version": "0.1.0",
+      "workspaces": [
+        "packages/*"
+      ],
       "dependencies": {
         "@fontsource-variable/inconsolata": "^5.2.7",
         "@fontsource/m-plus-rounded-1c": "^5.2.9",
@@ -3477,6 +3480,10 @@
         "@jridgewell/sourcemap-codec": "^1.4.14"
       }
     },
+    "node_modules/@my-code/js-eval": {
+      "resolved": "packages/jsEval",
+      "link": true
+    },
     "node_modules/@napi-rs/wasm-runtime": {
       "version": "0.2.12",
       "resolved": "https://registry.npmjs.org/@napi-rs/wasm-runtime/-/wasm-runtime-0.2.12.tgz",
@@ -8059,6 +8066,7 @@
       "integrity": "sha512-whOE1HFo/qJDyX4SnXzP4N6zOWn79WhnCUY/iDR0mPfQZO8wcYE4JClzI2oZrhBnnMUCBCHZhO6VQyoBU95mZA==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@rtsao/scc": "^1.1.0",
         "array-includes": "^3.1.9",
@@ -15613,6 +15621,14 @@
         "type": "github",
         "url": "https://github.com/sponsors/wooorm"
       }
+    },
+    "packages/jsEval": {
+      "name": "@my-code/js-eval",
+      "version": "0.1.0",
+      "devDependencies": {
+        "tsx": "*",
+        "typescript": "*"
+      }
     }
   }
 }
diff --git a/package.json b/package.json
index 29e08269..963fbb91 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,9 @@
   "version": "0.1.0",
   "private": true,
   "type": "module",
+  "workspaces": [
+    "packages/*"
+  ],
   "scripts": {
     "dev": "npm run cf-typegen && npm run generateLanguages && npm run generateSections && npm run copyAllDTSFiles && npm run removeHinting && next dev",
     "build": "npm run cf-typegen && npm run generateLanguages && npm run generateSections && npm run copyAllDTSFiles && npm run removeHinting && next build",
diff --git a/packages/jsEval/package.json b/packages/jsEval/package.json
new file mode 100644
index 00000000..f4048e78
--- /dev/null
+++ b/packages/jsEval/package.json
@@ -0,0 +1,16 @@
+{
+  "name": "@my-code/js-eval",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "exports": {
+    ".": "./src/index.ts"
+  },
+  "scripts": {
+    "test": "node --import tsx/esm --test src/index.test.ts"
+  },
+  "devDependencies": {
+    "tsx": "*",
+    "typescript": "*"
+  }
+}
diff --git a/packages/jsEval/src/index.test.ts b/packages/jsEval/src/index.test.ts
new file mode 100644
index 00000000..233a085a
--- /dev/null
+++ b/packages/jsEval/src/index.test.ts
@@ -0,0 +1,205 @@
+import { describe, it } from "node:test";
+import assert from "node:assert/strict";
+import { replLikeEval, checkSyntax } from "./index.ts";
+
+// ---------------------------------------------------------------------------
+// replLikeEval
+// ---------------------------------------------------------------------------
+
+describe("replLikeEval", () => {
+  describe("var declaration", () => {
+    it("evaluates var and returns undefined", async () => {
+      const result = await replLikeEval("var x = 42");
+      assert.strictEqual(result, undefined);
+    });
+  });
+
+  describe("const declaration", () => {
+    it("converts const to var and returns undefined", async () => {
+      const result = await replLikeEval("const constVar = 1");
+      assert.strictEqual(result, undefined);
+    });
+  });
+
+  describe("let declaration", () => {
+    it("converts let to var and returns undefined", async () => {
+      const result = await replLikeEval("let letVar = 2");
+      assert.strictEqual(result, undefined);
+    });
+  });
+
+  describe("undeclared variable assignment", () => {
+    it("assigns to global and returns the assigned value", async () => {
+      const result = await replLikeEval("undeclaredVar = 99");
+      assert.strictEqual(result, 99);
+    });
+  });
+
+  describe("expression evaluation", () => {
+    it("returns numeric result", async () => {
+      assert.strictEqual(await replLikeEval("1 + 2"), 3);
+    });
+
+    it("returns string result", async () => {
+      assert.strictEqual(await replLikeEval('"hello"'), "hello");
+    });
+
+    it("returns boolean result", async () => {
+      assert.strictEqual(await replLikeEval("true"), true);
+    });
+  });
+
+  describe("function declaration", () => {
+    it("declares a function and returns undefined", async () => {
+      const result = await replLikeEval("function greet() { return 'hi'; }");
+      assert.strictEqual(result, undefined);
+    });
+  });
+
+  describe("class declaration", () => {
+    it("converts class to var-assigned class expression and returns undefined", async () => {
+      const result = await replLikeEval("class MyClass { constructor() {} }");
+      assert.strictEqual(result, undefined);
+    });
+  });
+
+  describe("array literal", () => {
+    it("returns an array", async () => {
+      const result = await replLikeEval("[1, 2, 3]");
+      assert.deepStrictEqual(result, [1, 2, 3]);
+    });
+
+    it("returns an empty array", async () => {
+      assert.deepStrictEqual(await replLikeEval("[]"), []);
+    });
+  });
+
+  describe("object literal", () => {
+    it("returns an object for { a: 1 }", async () => {
+      const result = await replLikeEval("{ a: 1 }");
+      assert.deepStrictEqual(result, { a: 1 });
+    });
+
+    it("returns an empty object for {}", async () => {
+      assert.deepStrictEqual(await replLikeEval("{}"), {});
+    });
+  });
+
+  describe("block that looks like an object", () => {
+    it("executes a labelled statement block and returns undefined", async () => {
+      // { x: 1 } is ambiguous – first tried as object; if that fails as
+      // SyntaxError it falls back to block execution. A true label statement
+      // `{ label: expr; }` is a block and eval returns the last expression.
+      // { a: 1 } is valid as both, so replLikeEval returns the object.
+      const result = await replLikeEval("{ x: 1 }");
+      // Treated as object literal when it is valid JSON-like
+      assert.deepStrictEqual(result, { x: 1 });
+    });
+
+    it("executes pure block statement when object parse fails", async () => {
+      // A block containing a statement that is invalid as an object expression
+      // forces the fallback path.
+      const result = await replLikeEval("{ let tmp = 5; tmp; }");
+      assert.strictEqual(result, 5);
+    });
+  });
+
+  describe("await expression", () => {
+    it("awaits a resolved promise", async () => {
+      const result = await replLikeEval("await Promise.resolve(7)");
+      assert.strictEqual(result, 7);
+    });
+  });
+
+  describe("error propagation", () => {
+    it("throws ReferenceError for undefined identifier", async () => {
+      await assert.rejects(
+        () => replLikeEval("notDefinedAtAllXyz"),
+        ReferenceError
+      );
+    });
+  });
+});
+
+// ---------------------------------------------------------------------------
+// checkSyntax
+// ---------------------------------------------------------------------------
+
+describe("checkSyntax", () => {
+  describe("complete inputs", () => {
+    it("simple expression is complete", async () => {
+      assert.deepStrictEqual(await checkSyntax("1 + 2"), {
+        status: "complete",
+      });
+    });
+
+    it("function declaration is complete", async () => {
+      assert.deepStrictEqual(
+        await checkSyntax("function f() { return 1; }"),
+        { status: "complete" }
+      );
+    });
+
+    it("if-else block is complete", async () => {
+      assert.deepStrictEqual(
+        await checkSyntax("if (true) { 1; } else { 2; }"),
+        { status: "complete" }
+      );
+    });
+
+    it("for loop is complete", async () => {
+      assert.deepStrictEqual(
+        await checkSyntax("for (let i = 0; i < 3; i++) {}"),
+        { status: "complete" }
+      );
+    });
+
+    it("empty string is complete", async () => {
+      assert.deepStrictEqual(await checkSyntax(""), { status: "complete" });
+    });
+  });
+
+  describe("incomplete inputs", () => {
+    it("if(1){ is incomplete", async () => {
+      assert.deepStrictEqual(await checkSyntax("if(1){"), {
+        status: "incomplete",
+      });
+    });
+
+    it("function f() { is incomplete", async () => {
+      assert.deepStrictEqual(await checkSyntax("function f() {"), {
+        status: "incomplete",
+      });
+    });
+
+    it("open array bracket is incomplete", async () => {
+      assert.deepStrictEqual(await checkSyntax("[1, 2,"), {
+        status: "incomplete",
+      });
+    });
+
+    it("open object brace is incomplete", async () => {
+      assert.deepStrictEqual(await checkSyntax("({ a:"), {
+        status: "incomplete",
+      });
+    });
+  });
+
+  describe("invalid inputs", () => {
+    it("extra closing brace after complete block returns incomplete (extra } matches wrapper)", async () => {
+      // The implementation wraps code in `() => {<code>}`.
+      // An extra } is interpreted as closing the wrapper early, so the
+      // engine reports "Unexpected token '}'" – which the heuristic maps to
+      // "incomplete".  This is a known limitation of the wrapper approach.
+      assert.deepStrictEqual(await checkSyntax("if(1){}}"), {
+        status: "incomplete",
+      });
+    });
+
+    it("syntax error expression is invalid", async () => {
+      assert.deepStrictEqual(await checkSyntax("1 +* 2"), {
+        status: "invalid",
+      });
+    });
+  });
+});
diff --git a/packages/jsEval/src/index.ts b/packages/jsEval/src/index.ts
new file mode 100644
index 00000000..fe062460
--- /dev/null
+++ b/packages/jsEval/src/index.ts
@@ -0,0 +1,65 @@
+// Use indirect eval so that var declarations go to the global scope,
+// matching the behaviour of a REPL where variables persist across calls.
+// Security note: eval is intentionally used here to implement a JavaScript
+// REPL. This package must only be loaded in an isolated context (e.g. a Web
+// Worker or a sandboxed Node.js process) where arbitrary code execution is
+// the expected behaviour.
+// eslint-disable-next-line no-eval
+const indirectEval: (code: string) => unknown = (0, eval);
+
+export async function replLikeEval(code: string): Promise<unknown> {
+  // eval()の中でconst,letを使って変数を作成した場合、
+  // 次に実行するコマンドはスコープ外扱いでありアクセスできなくなってしまうので、
+  // varに置き換えている
+  if (code.trim().startsWith("const ")) {
+    code = "var " + code.trim().slice(6);
+  } else if (code.trim().startsWith("let ")) {
+    code = "var " + code.trim().slice(4);
+  }
+  // eval()の中でclassを作成した場合も同様
+  const classRegExp = /^\s*class\s+(\w+)/;
+  if (classRegExp.test(code)) {
+    code = code.replace(classRegExp, "var $1 = class $1");
+  }
+
+  if (code.trim().startsWith("{") && code.trim().endsWith("}")) {
+    // オブジェクトは ( ) で囲わなければならない
+    try {
+      return indirectEval(`(${code})`);
+    } catch (e) {
+      if (e instanceof SyntaxError) {
+        // オブジェクトではなくブロックだった場合、再度普通に実行
+        return indirectEval(code);
+      } else {
+        throw e;
+      }
+    }
+  } else if (/^\s*await\W/.test(code)) {
+    // promiseをawaitする場合は、promiseの部分だけをevalし、それを外からawaitする
+    return await (indirectEval(code.trim().slice(5)) as Promise<unknown>);
+  } else {
+    return indirectEval(code);
+  }
+}
+
+export async function checkSyntax(
+  code: string
+): Promise<{ status: "complete" | "incomplete" | "invalid" }> {
+  try {
+    indirectEval(`() => {${code}}`);
+    return { status: "complete" };
+  } catch (e) {
+    if (e instanceof SyntaxError) {
+      if (
+        e.message.includes("Unexpected token '}'") ||
+        e.message.includes("Unexpected end of input")
+      ) {
+        return { status: "incomplete" };
+      } else {
+        return { status: "invalid" };
+      }
+    } else {
+      return { status: "invalid" };
+    }
+  }
+}
diff --git a/packages/jsEval/tsconfig.json b/packages/jsEval/tsconfig.json
new file mode 100644
index 00000000..437cdfe8
--- /dev/null
+++ b/packages/jsEval/tsconfig.json
@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true
+  },
+  "include": ["src"]
+}

From 459a5e552d83026bac7f98afcfdf63f3d12e8330 Mon Sep 17 00:00:00 2001
From: na-trium-144 <100704180+na-trium-144@users.noreply.github.com>
Date: Thu, 26 Feb 2026 16:49:49 +0900
Subject: [PATCH 3/3] =?UTF-8?q?=E3=83=95=E3=82=A1=E3=82=A4=E3=83=AB?=
 =?UTF-8?q?=E5=88=86=E5=89=B2?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 package-lock.json                             | 39 ++------
 packages/jsEval/package.json                  |  6 +-
 packages/jsEval/src/eval.ts                   | 43 +++++++++
 packages/jsEval/src/index.ts                  | 67 +-------------
 packages/jsEval/src/syntax.ts                 | 24 +++++
 .../{src/index.test.ts => tests/eval.spec.ts} | 89 +------------------
 packages/jsEval/tests/syntax.spec.ts          | 81 +++++++++++++++++
 packages/jsEval/tsconfig.json                 |  5 +-
 8 files changed, 163 insertions(+), 191 deletions(-)
 create mode 100644 packages/jsEval/src/eval.ts
 create mode 100644 packages/jsEval/src/syntax.ts
 rename packages/jsEval/{src/index.test.ts => tests/eval.spec.ts} (58%)
 create mode 100644 packages/jsEval/tests/syntax.spec.ts

diff --git a/package-lock.json b/package-lock.json
index 74830297..53b95448 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1500,7 +1500,6 @@
       "version": "1.4.5",
       "resolved": "https://registry.npmjs.org/@better-auth/core/-/core-1.4.5.tgz",
       "integrity": "sha512-dQ3hZOkUJzeBXfVEPTm2LVbzmWwka1nqd9KyWmB2OMlMfjr7IdUeBX4T7qJctF67d7QDhlX95jMoxu6JG0Eucw==",
-      "peer": true,
       "dependencies": {
         "@standard-schema/spec": "^1.0.0",
         "zod": "^4.1.12"
@@ -1530,14 +1529,12 @@
       "version": "0.3.0",
       "resolved": "https://registry.npmjs.org/@better-auth/utils/-/utils-0.3.0.tgz",
       "integrity": "sha512-W+Adw6ZA6mgvnSnhOki270rwJ42t4XzSK6YWGF//BbVXL6SwCLWfyzBc1lN2m/4RM28KubdBKQ4X5VMoLRNPQw==",
-      "license": "MIT",
-      "peer": true
+      "license": "MIT"
     },
     "node_modules/@better-fetch/fetch": {
       "version": "1.1.18",
       "resolved": "https://registry.npmjs.org/@better-fetch/fetch/-/fetch-1.1.18.tgz",
-      "integrity": "sha512-rEFOE1MYIsBmoMJtQbl32PGHHXuG2hDxvEd7rUHE0vCBoFQVSDqaVs9hkZEtHCxRoY+CljXKFCOuJ8uxqw1LcA==",
-      "peer": true
+      "integrity": "sha512-rEFOE1MYIsBmoMJtQbl32PGHHXuG2hDxvEd7rUHE0vCBoFQVSDqaVs9hkZEtHCxRoY+CljXKFCOuJ8uxqw1LcA=="
     },
     "node_modules/@bjorn3/browser_wasi_shim": {
       "version": "0.3.0",
@@ -1735,7 +1732,6 @@
       "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-4.0.3.tgz",
       "integrity": "sha512-5gTmgEY/sqK6gFXLIsQNH19lWb4ebPDLA4SdLP7dsWkIXHWlG66oPuVvXSGFPppYZz8ZDZq0dYYrbHfBCVUb1Q==",
       "license": "MIT",
-      "peer": true,
       "engines": {
         "node": ">=12"
       },
@@ -3646,7 +3642,6 @@
       "resolved": "https://registry.npmjs.org/@noble/ciphers/-/ciphers-1.3.0.tgz",
       "integrity": "sha512-2I0gnIVPtfnMw9ee9h1dJG7tp81+8Ob3OJb3Mv37rx5L40/b0i7djjCVvGOVqc9AEIQyvyu1i6ypKdFw8R8gQw==",
       "license": "MIT",
-      "peer": true,
       "engines": {
         "node": "^14.21.3 || >=16"
       },
@@ -5297,7 +5292,6 @@
       "integrity": "sha512-LF7lF6zWEKxuT3/OR8wAZGzkg4ENGXFNyiV/JeOt9z5B+0ZVwbql9McqX5c/WStFq1GaGso7H1AzP/qSzmlCKQ==",
       "devOptional": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@types/node": "*",
         "pg-protocol": "*",
@@ -5315,7 +5309,6 @@
       "resolved": "https://registry.npmjs.org/@types/react/-/react-19.2.7.tgz",
       "integrity": "sha512-MWtvHrGZLFttgeEj28VXHxpmwYbor/ATPYbBfSFZEIRK0ecCFLl2Qo55z52Hss+UV9CRN7trSeq1zbgx7YDWWg==",
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "csstype": "^3.2.2"
       }
@@ -5391,7 +5384,6 @@
       "integrity": "sha512-IgSWvLobTDOjnaxAfDTIHaECbkNlAlKv2j5SjpB2v7QHKv1FIfjwMy8FsDbVfDX/KjmCmYICcw7uGaXLhtsLNg==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@typescript-eslint/scope-manager": "8.56.0",
         "@typescript-eslint/types": "8.56.0",
@@ -5939,8 +5931,7 @@
       "version": "5.6.0-beta.115",
       "resolved": "https://registry.npmjs.org/@xterm/xterm/-/xterm-5.6.0-beta.115.tgz",
       "integrity": "sha512-EJXAW6dbxPuwQnLfTmPB5R3M5uu8qp24ltHdjCcfwGpudKxQRoDEbq1IeGrVLIuRc/8TbnT1U07dXUX7kyGYEQ==",
-      "license": "MIT",
-      "peer": true
+      "license": "MIT"
     },
     "node_modules/abort-controller": {
       "version": "3.0.0",
@@ -5978,7 +5969,6 @@
       "resolved": "https://registry.npmjs.org/acorn/-/acorn-8.15.0.tgz",
       "integrity": "sha512-NZyJarBfL7nWwIq+FDL6Zp/yHEhePMNnnJ0y3qfieCrmNvYct8uvtiV41UvlSe6apAfk0fY1FbWx+NwfmpvtTg==",
       "license": "MIT",
-      "peer": true,
       "bin": {
         "acorn": "bin/acorn"
       },
@@ -6462,7 +6452,6 @@
       "resolved": "https://registry.npmjs.org/better-call/-/better-call-1.1.4.tgz",
       "integrity": "sha512-NJouLY6IVKv0nDuFoc6FcbKDFzEnmgMNofC9F60Mwx1Ecm7X6/Ecyoe5b+JSVZ42F/0n46/M89gbYP1ZCVv8xQ==",
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@better-auth/utils": "^0.3.0",
         "@better-fetch/fetch": "^1.1.4",
@@ -7811,7 +7800,6 @@
       "integrity": "sha512-8pgjLUcUjcgDg+2Q4NYXnPbo/vncAY4UmyaCm0jZevERqCHZIaWwdJHkf8XQtu4AxSKCdvrUbT0XUr1IdZzI8Q==",
       "hasInstallScript": true,
       "license": "MIT",
-      "peer": true,
       "bin": {
         "esbuild": "bin/esbuild"
       },
@@ -7892,7 +7880,6 @@
       "integrity": "sha512-VmQ+sifHUbI/IcSopBCF/HO3YiHQx/AVd3UVyYL6weuwW+HvON9VYn5l6Zl1WZzPWXPNZrSQpxwkkZ/VuvJZzg==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@eslint-community/eslint-utils": "^4.8.0",
         "@eslint-community/regexpp": "^4.12.1",
@@ -8066,7 +8053,6 @@
       "integrity": "sha512-whOE1HFo/qJDyX4SnXzP4N6zOWn79WhnCUY/iDR0mPfQZO8wcYE4JClzI2oZrhBnnMUCBCHZhO6VQyoBU95mZA==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@rtsao/scc": "^1.1.0",
         "array-includes": "^3.1.9",
@@ -10078,7 +10064,6 @@
       "resolved": "https://registry.npmjs.org/jose/-/jose-6.1.3.tgz",
       "integrity": "sha512-0TpaTfihd4QMNwrz/ob2Bp7X04yuxJkjRGi4aKmOqwhov54i6u79oCv7T+C7lo70MKH6BesI3vscD1yb/yzKXQ==",
       "license": "MIT",
-      "peer": true,
       "funding": {
         "url": "https://github.com/sponsors/panva"
       }
@@ -10205,7 +10190,6 @@
       "resolved": "https://registry.npmjs.org/kysely/-/kysely-0.28.8.tgz",
       "integrity": "sha512-QUOgl5ZrS9IRuhq5FvOKFSsD/3+IA6MLE81/bOOTRA/YQpKDza2sFdN5g6JCB9BOpqMJDGefLCQ9F12hRS13TA==",
       "license": "MIT",
-      "peer": true,
       "engines": {
         "node": ">=20.0.0"
       }
@@ -10959,7 +10943,6 @@
         }
       ],
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@types/debug": "^4.0.0",
         "debug": "^4.0.0",
@@ -11550,8 +11533,7 @@
           "url": "https://opencollective.com/unified"
         }
       ],
-      "license": "MIT",
-      "peer": true
+      "license": "MIT"
     },
     "node_modules/micromatch": {
       "version": "4.0.8",
@@ -11944,7 +11926,6 @@
         }
       ],
       "license": "MIT",
-      "peer": true,
       "engines": {
         "node": "^20.0.0 || >=22.0.0"
       }
@@ -11986,7 +11967,6 @@
       "resolved": "https://registry.npmjs.org/next/-/next-15.5.11.tgz",
       "integrity": "sha512-L2KPiKmqTDpRdeVDdPjhf43g2/VPe0NCNndq7OKDCgOLWtxe1kbr/zXGIZtYY7kZEAjRf7Bj/mwUFSr+tYC2Yg==",
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@next/env": "15.5.11",
         "@swc/helpers": "0.5.15",
@@ -12511,7 +12491,6 @@
       "resolved": "https://registry.npmjs.org/pg/-/pg-8.16.3.tgz",
       "integrity": "sha512-enxc1h0jA/aq5oSDMvqyW3q89ra6XIIDZgCX9vkMrnz5DFTw/Ny3Li2lFQ+pt3L6MCgm/5o2o8HW9hiJji+xvw==",
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "pg-connection-string": "^2.9.1",
         "pg-pool": "^3.10.1",
@@ -14178,7 +14157,6 @@
       "integrity": "sha512-5gTmgEY/sqK6gFXLIsQNH19lWb4ebPDLA4SdLP7dsWkIXHWlG66oPuVvXSGFPppYZz8ZDZq0dYYrbHfBCVUb1Q==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "engines": {
         "node": ">=12"
       },
@@ -14402,7 +14380,6 @@
       "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
       "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
       "license": "Apache-2.0",
-      "peer": true,
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
@@ -14450,7 +14427,6 @@
       "resolved": "https://registry.npmjs.org/unenv/-/unenv-2.0.0-rc.24.tgz",
       "integrity": "sha512-i7qRCmY42zmCwnYlh9H2SvLEypEFGye5iRmEMKjcGi7zk9UquigRjFtTLz0TYqr0ZGLZhaMHl/foy1bZR+Cwlw==",
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "pathe": "^2.0.3"
       }
@@ -14460,7 +14436,6 @@
       "resolved": "https://registry.npmjs.org/unified/-/unified-11.0.5.tgz",
       "integrity": "sha512-xKvGhPWw3k84Qjh8bI3ZeJjqnyadK+GEFtazSfZv/rKeTkTjOJho6mFqh2SM96iIcZokxiOpg78GazTSg8+KHA==",
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@types/unist": "^3.0.0",
         "bail": "^2.0.0",
@@ -14807,7 +14782,6 @@
       "integrity": "sha512-EhLJGptSGFi8AEErLiamO3PoGpbRqL+v4Ve36H2B38VxmDgFOSmDhfepBnA14sCQzGf1AEaoZX2DCwZsmO74yQ==",
       "hasInstallScript": true,
       "license": "Apache-2.0",
-      "peer": true,
       "bin": {
         "workerd": "bin/workerd"
       },
@@ -14833,7 +14807,6 @@
       "resolved": "https://registry.npmjs.org/wrangler/-/wrangler-4.61.1.tgz",
       "integrity": "sha512-hfYQ16VLPkNi8xE1/V3052S2stM5e+vq3Idpt83sXoDC3R7R1CLgMkK6M6+Qp3G+9GVDNyHCkvohMPdfFTaD4Q==",
       "license": "MIT OR Apache-2.0",
-      "peer": true,
       "dependencies": {
         "@cloudflare/kv-asset-handler": "0.4.2",
         "@cloudflare/unenv-preset": "2.12.0",
@@ -15626,8 +15599,8 @@
       "name": "@my-code/js-eval",
       "version": "0.1.0",
       "devDependencies": {
-        "tsx": "*",
-        "typescript": "*"
+        "tsx": "^4",
+        "typescript": "^5"
       }
     }
   }
diff --git a/packages/jsEval/package.json b/packages/jsEval/package.json
index f4048e78..c62edc57 100644
--- a/packages/jsEval/package.json
+++ b/packages/jsEval/package.json
@@ -7,10 +7,10 @@
     ".": "./src/index.ts"
   },
   "scripts": {
-    "test": "node --import tsx/esm --test src/index.test.ts"
+    "test": "node --import tsx/esm --test tests/*"
   },
   "devDependencies": {
-    "tsx": "*",
-    "typescript": "*"
+    "tsx": "^4",
+    "typescript": "^5"
   }
 }
diff --git a/packages/jsEval/src/eval.ts b/packages/jsEval/src/eval.ts
new file mode 100644
index 00000000..74177849
--- /dev/null
+++ b/packages/jsEval/src/eval.ts
@@ -0,0 +1,43 @@
+// Use indirect eval so that var declarations go to the global scope,
+// matching the behaviour of a REPL where variables persist across calls.
+// Security note: eval is intentionally used here to implement a JavaScript
+// REPL. This package must only be loaded in an isolated context (e.g. a Web
+// Worker or a sandboxed Node.js process) where arbitrary code execution is
+// the expected behaviour.
+// @ts-expect-error comma operator for indirect eval
+const indirectEval: (code: string) => unknown = (0, eval);
+
+export async function replLikeEval(code: string): Promise<unknown> {
+  // eval()の中でconst,letを使って変数を作成した場合、
+  // 次に実行するコマンドはスコープ外扱いでありアクセスできなくなってしまうので、
+  // varに置き換えている
+  if (code.trim().startsWith("const ")) {
+    code = "var " + code.trim().slice(6);
+  } else if (code.trim().startsWith("let ")) {
+    code = "var " + code.trim().slice(4);
+  }
+  // eval()の中でclassを作成した場合も同様
+  const classRegExp = /^\s*class\s+(\w+)/;
+  if (classRegExp.test(code)) {
+    code = code.replace(classRegExp, "var $1 = class $1");
+  }
+
+  if (code.trim().startsWith("{") && code.trim().endsWith("}")) {
+    // オブジェクトは ( ) で囲わなければならない
+    try {
+      return indirectEval(`(${code})`);
+    } catch (e) {
+      if (e instanceof SyntaxError) {
+        // オブジェクトではなくブロックだった場合、再度普通に実行
+        return indirectEval(code);
+      } else {
+        throw e;
+      }
+    }
+  } else if (/^\s*await\W/.test(code)) {
+    // promiseをawaitする場合は、promiseの部分だけをevalし、それを外からawaitする
+    return await (indirectEval(code.trim().slice(5)) as Promise<unknown>);
+  } else {
+    return indirectEval(code);
+  }
+}
diff --git a/packages/jsEval/src/index.ts b/packages/jsEval/src/index.ts
index fe062460..6a98a229 100644
--- a/packages/jsEval/src/index.ts
+++ b/packages/jsEval/src/index.ts
@@ -1,65 +1,2 @@
-// Use indirect eval so that var declarations go to the global scope,
-// matching the behaviour of a REPL where variables persist across calls.
-// Security note: eval is intentionally used here to implement a JavaScript
-// REPL. This package must only be loaded in an isolated context (e.g. a Web
-// Worker or a sandboxed Node.js process) where arbitrary code execution is
-// the expected behaviour.
-// eslint-disable-next-line no-eval
-const indirectEval: (code: string) => unknown = (0, eval);
-
-export async function replLikeEval(code: string): Promise<unknown> {
-  // eval()の中でconst,letを使って変数を作成した場合、
-  // 次に実行するコマンドはスコープ外扱いでありアクセスできなくなってしまうので、
-  // varに置き換えている
-  if (code.trim().startsWith("const ")) {
-    code = "var " + code.trim().slice(6);
-  } else if (code.trim().startsWith("let ")) {
-    code = "var " + code.trim().slice(4);
-  }
-  // eval()の中でclassを作成した場合も同様
-  const classRegExp = /^\s*class\s+(\w+)/;
-  if (classRegExp.test(code)) {
-    code = code.replace(classRegExp, "var $1 = class $1");
-  }
-
-  if (code.trim().startsWith("{") && code.trim().endsWith("}")) {
-    // オブジェクトは ( ) で囲わなければならない
-    try {
-      return indirectEval(`(${code})`);
-    } catch (e) {
-      if (e instanceof SyntaxError) {
-        // オブジェクトではなくブロックだった場合、再度普通に実行
-        return indirectEval(code);
-      } else {
-        throw e;
-      }
-    }
-  } else if (/^\s*await\W/.test(code)) {
-    // promiseをawaitする場合は、promiseの部分だけをevalし、それを外からawaitする
-    return await (indirectEval(code.trim().slice(5)) as Promise<unknown>);
-  } else {
-    return indirectEval(code);
-  }
-}
-
-export async function checkSyntax(
-  code: string
-): Promise<{ status: "complete" | "incomplete" | "invalid" }> {
-  try {
-    indirectEval(`() => {${code}}`);
-    return { status: "complete" };
-  } catch (e) {
-    if (e instanceof SyntaxError) {
-      if (
-        e.message.includes("Unexpected token '}'") ||
-        e.message.includes("Unexpected end of input")
-      ) {
-        return { status: "incomplete" };
-      } else {
-        return { status: "invalid" };
-      }
-    } else {
-      return { status: "invalid" };
-    }
-  }
-}
+export { replLikeEval } from "./eval";
+export { checkSyntax } from "./syntax";
diff --git a/packages/jsEval/src/syntax.ts b/packages/jsEval/src/syntax.ts
new file mode 100644
index 00000000..512e3625
--- /dev/null
+++ b/packages/jsEval/src/syntax.ts
@@ -0,0 +1,24 @@
+// @ts-expect-error comma operator for indirect eval
+const indirectEval: (code: string) => unknown = (0, eval);
+
+export async function checkSyntax(
+  code: string
+): Promise<{ status: "complete" | "incomplete" | "invalid" }> {
+  try {
+    indirectEval(`() => {${code}}`);
+    return { status: "complete" };
+  } catch (e) {
+    if (e instanceof SyntaxError) {
+      if (
+        e.message.includes("Unexpected token '}'") ||
+        e.message.includes("Unexpected end of input")
+      ) {
+        return { status: "incomplete" };
+      } else {
+        return { status: "invalid" };
+      }
+    } else {
+      return { status: "invalid" };
+    }
+  }
+}
diff --git a/packages/jsEval/src/index.test.ts b/packages/jsEval/tests/eval.spec.ts
similarity index 58%
rename from packages/jsEval/src/index.test.ts
rename to packages/jsEval/tests/eval.spec.ts
index 233a085a..0d0e2830 100644
--- a/packages/jsEval/src/index.test.ts
+++ b/packages/jsEval/tests/eval.spec.ts
@@ -1,10 +1,6 @@
 import { describe, it } from "node:test";
 import assert from "node:assert/strict";
-import { replLikeEval, checkSyntax } from "./index.ts";
-
-// ---------------------------------------------------------------------------
-// replLikeEval
-// ---------------------------------------------------------------------------
+import { replLikeEval } from "../src/index.js";
 
 describe("replLikeEval", () => {
   describe("var declaration", () => {
@@ -120,86 +116,3 @@ describe("replLikeEval", () => {
     });
   });
 });
-
-// ---------------------------------------------------------------------------
-// checkSyntax
-// ---------------------------------------------------------------------------
-
-describe("checkSyntax", () => {
-  describe("complete inputs", () => {
-    it("simple expression is complete", async () => {
-      assert.deepStrictEqual(await checkSyntax("1 + 2"), {
-        status: "complete",
-      });
-    });
-
-    it("function declaration is complete", async () => {
-      assert.deepStrictEqual(
-        await checkSyntax("function f() { return 1; }"),
-        { status: "complete" }
-      );
-    });
-
-    it("if-else block is complete", async () => {
-      assert.deepStrictEqual(
-        await checkSyntax("if (true) { 1; } else { 2; }"),
-        { status: "complete" }
-      );
-    });
-
-    it("for loop is complete", async () => {
-      assert.deepStrictEqual(
-        await checkSyntax("for (let i = 0; i < 3; i++) {}"),
-        { status: "complete" }
-      );
-    });
-
-    it("empty string is complete", async () => {
-      assert.deepStrictEqual(await checkSyntax(""), { status: "complete" });
-    });
-  });
-
-  describe("incomplete inputs", () => {
-    it("if(1){ is incomplete", async () => {
-      assert.deepStrictEqual(await checkSyntax("if(1){"), {
-        status: "incomplete",
-      });
-    });
-
-    it("function f() { is incomplete", async () => {
-      assert.deepStrictEqual(await checkSyntax("function f() {"), {
-        status: "incomplete",
-      });
-    });
-
-    it("open array bracket is incomplete", async () => {
-      assert.deepStrictEqual(await checkSyntax("[1, 2,"), {
-        status: "incomplete",
-      });
-    });
-
-    it("open object brace is incomplete", async () => {
-      assert.deepStrictEqual(await checkSyntax("({ a:"), {
-        status: "incomplete",
-      });
-    });
-  });
-
-  describe("invalid inputs", () => {
-    it("extra closing brace after complete block returns incomplete (extra } matches wrapper)", async () => {
-      // The implementation wraps code in `() => {<code>}`.
-      // An extra } is interpreted as closing the wrapper early, so the
-      // engine reports "Unexpected token '}'" – which the heuristic maps to
-      // "incomplete".  This is a known limitation of the wrapper approach.
-      assert.deepStrictEqual(await checkSyntax("if(1){}}"), {
-        status: "incomplete",
-      });
-    });
-
-    it("syntax error expression is invalid", async () => {
-      assert.deepStrictEqual(await checkSyntax("1 +* 2"), {
-        status: "invalid",
-      });
-    });
-  });
-});
diff --git a/packages/jsEval/tests/syntax.spec.ts b/packages/jsEval/tests/syntax.spec.ts
new file mode 100644
index 00000000..901da5d9
--- /dev/null
+++ b/packages/jsEval/tests/syntax.spec.ts
@@ -0,0 +1,81 @@
+import { describe, it } from "node:test";
+import assert from "node:assert/strict";
+import { checkSyntax } from "../src/index.js";
+
+describe("checkSyntax", () => {
+  describe("complete inputs", () => {
+    it("simple expression is complete", async () => {
+      assert.deepStrictEqual(await checkSyntax("1 + 2"), {
+        status: "complete",
+      });
+    });
+
+    it("function declaration is complete", async () => {
+      assert.deepStrictEqual(await checkSyntax("function f() { return 1; }"), {
+        status: "complete",
+      });
+    });
+
+    it("if-else block is complete", async () => {
+      assert.deepStrictEqual(
+        await checkSyntax("if (true) { 1; } else { 2; }"),
+        { status: "complete" }
+      );
+    });
+
+    it("for loop is complete", async () => {
+      assert.deepStrictEqual(
+        await checkSyntax("for (let i = 0; i < 3; i++) {}"),
+        { status: "complete" }
+      );
+    });
+
+    it("empty string is complete", async () => {
+      assert.deepStrictEqual(await checkSyntax(""), { status: "complete" });
+    });
+  });
+
+  describe("incomplete inputs", () => {
+    it("if(1){ is incomplete", async () => {
+      assert.deepStrictEqual(await checkSyntax("if(1){"), {
+        status: "incomplete",
+      });
+    });
+
+    it("function f() { is incomplete", async () => {
+      assert.deepStrictEqual(await checkSyntax("function f() {"), {
+        status: "incomplete",
+      });
+    });
+
+    it("open array bracket is incomplete", async () => {
+      assert.deepStrictEqual(await checkSyntax("[1, 2,"), {
+        status: "incomplete",
+      });
+    });
+
+    it("open object brace is incomplete", async () => {
+      assert.deepStrictEqual(await checkSyntax("({ a:"), {
+        status: "incomplete",
+      });
+    });
+  });
+
+  describe("invalid inputs", () => {
+    it("extra closing brace after complete block returns incomplete (extra } matches wrapper)", async () => {
+      // The implementation wraps code in `() => {<code>}`.
+      // An extra } is interpreted as closing the wrapper early, so the
+      // engine reports "Unexpected token '}'" – which the heuristic maps to
+      // "incomplete".  This is a known limitation of the wrapper approach.
+      assert.deepStrictEqual(await checkSyntax("if(1){}}"), {
+        status: "incomplete",
+      });
+    });
+
+    it("syntax error expression is invalid", async () => {
+      assert.deepStrictEqual(await checkSyntax("1 +* 2"), {
+        status: "invalid",
+      });
+    });
+  });
+});
diff --git a/packages/jsEval/tsconfig.json b/packages/jsEval/tsconfig.json
index 437cdfe8..9cae755c 100644
--- a/packages/jsEval/tsconfig.json
+++ b/packages/jsEval/tsconfig.json
@@ -2,10 +2,11 @@
   "compilerOptions": {
     "target": "ES2022",
     "module": "NodeNext",
-    "moduleResolution": "NodeNext",
+    "moduleResolution": "bundler",
     "strict": true,
     "esModuleInterop": true,
-    "skipLibCheck": true
+    "skipLibCheck": true,
+    "noEmit": true
   },
   "include": ["src"]
 }