fix(code-runtime): validate arguments before worker dispatch

packages/code-runtime/code-runtime-worker/tests/bootstrap.spec.ts

@@ -190,7 +190,7 @@ describe('makeNamespaces', () => {
     await expect(tools['toString']?.({})).resolves.toBe('toString-ok')
   })
 
-  it('rejects a non-cloneable argument without leaking the pending entry', async () => {
+  it('rejects a postMessage clone failure without leaking the pending entry', async () => {
     let firstCall = true
     const throwingPort: BootstrapPort = {
       // First call throws an Error (the real DataCloneError shape), the
@@ -203,8 +203,8 @@ describe('makeNamespaces', () => {
     }
     const pending = new Map<number, PendingCall>()
     const [tools] = makeNamespaces({ namespaces: [{ global: 'tools', names: ['x'] }] }, throwingPort, pending, { value: 1 }) as [Record<string, (args: unknown) => Promise<unknown>>]
-    const first = await rejectionOf(tools.x?.(() => 1) ?? Promise.resolve())
-    const second = await rejectionOf(tools.x?.(() => 1) ?? Promise.resolve())
+    const first = await rejectionOf(tools.x?.({ first: true }) ?? Promise.resolve())
+    const second = await rejectionOf(tools.x?.({ second: true }) ?? Promise.resolve())
     expect(first).toMatchObject({ name: 'ToolCallError', toolName: 'x' })
     expect(second).toMatchObject({ name: 'ToolCallError', toolName: 'x' })
     expect(first).toBeInstanceOf(ToolCallError)
@@ -214,6 +214,32 @@ describe('makeNamespaces', () => {
     expect(pending.size).toBe(0)
   })
 
+  it('rejects lossy arguments before posting or allocating a call id', async () => {
+    let posts = 0
+    const port: BootstrapPort = { postMessage: () => { posts += 1 }, on: () => {} }
+    const pending = new Map<number, PendingCall>()
+    const nextId = { value: 1 }
+    const [tools] = makeNamespaces(
+      { namespaces: [{ global: 'tools', names: ['x'] }] }, port, pending, nextId,
+    ) as [Record<string, (args: unknown) => Promise<unknown>>]
+    const decorated = [1]
+    Object.defineProperty(decorated, 'extra', { value: true })
+    const throwing = Object.defineProperty({}, 'value', {
+      enumerable: true,
+      get: () => { throw new Error('getter exploded') },
+    })
+
+    for (const value of [() => 1, new Date(), decorated, throwing]) {
+      const failure = await rejectionOf(tools.x?.(value) ?? Promise.resolve())
+      expect(failure).toMatchObject({
+        name: 'ToolCallError', toolName: 'x', message: 'binding arguments must be lossless JSON',
+      })
+    }
+    expect(posts).toBe(0)
+    expect(pending.size).toBe(0)
+    expect(nextId.value).toBe(1)
+  })
+
   it('uses ordinary Error for non-tools namespace failures', async () => {
     const deniedPort = new FakePort()
     deniedPort.respond = message => message.type === 'call'
@@ -226,9 +252,14 @@ describe('makeNamespaces', () => {
     expect(denied).toBeInstanceOf(Error)
     expect(denied).not.toBeInstanceOf(ToolCallError)
 
+    const invalid = await rejectionOf(helpers.x?.(() => 1) ?? Promise.resolve())
+    expect(invalid).toBeInstanceOf(Error)
+    expect(invalid).not.toBeInstanceOf(ToolCallError)
+    expect((invalid as Error).message).toBe('binding arguments must be lossless JSON')
+
     const clonePort: BootstrapPort = { postMessage: () => { throw new Error('clone failed') }, on: () => {} }
     const [cloneHelpers] = makeNamespaces({ namespaces: [{ global: 'helpers', names: ['x'] }] }, clonePort, new Map(), { value: 1 }) as [Record<string, (args: unknown) => Promise<unknown>>]
-    const cloneFailure = await rejectionOf(cloneHelpers.x?.(() => 1) ?? Promise.resolve())
+    const cloneFailure = await rejectionOf(cloneHelpers.x?.({}) ?? Promise.resolve())
     expect(cloneFailure).toBeInstanceOf(Error)
     expect(cloneFailure).not.toBeInstanceOf(ToolCallError)
   })

packages/code-runtime/code-runtime-worker/tests/output-json.spec.ts

@@ -0,0 +1,18 @@
+import { describe, expect, it } from 'vitest'
+import { truncateJsonStringBytes } from '../src/output-json.ts'
+
+describe('truncateJsonStringBytes', () => {
+  it('returns a fitting string whole and rejects budgets without JSON quotes', () => {
+    expect(truncateJsonStringBytes('fits', 6)).toBe('fits')
+    expect(truncateJsonStringBytes('x', 1)).toBe('')
+  })
+
+  it('accounts every JSON escape and cuts only between complete code points', () => {
+    const prefix = '"\\\b\t\n\f\r\u0000😀\ud800€a'
+    const text = `${prefix}z`
+    const budget = Buffer.byteLength(JSON.stringify(prefix), 'utf8')
+
+    expect(truncateJsonStringBytes(text, budget)).toBe(prefix)
+    expect(Buffer.byteLength(JSON.stringify(truncateJsonStringBytes(text, budget)), 'utf8')).toBe(budget)
+  })
+})

packages/code-runtime/code-runtime-worker/tests/runtime.spec.ts

@@ -218,6 +218,19 @@ describe('WorkerCodeRuntime — budgets and containment (real workers)', () => {
     expect(Buffer.byteLength(JSON.stringify(result.logs), 'utf8')).toBeLessThan(300)
   })
 
+  it('retains a fitting prefix when one oversized log is the first output', async () => {
+    const { runtime } = await setup({ maxOutputBytes: 96 })
+    const result = await runtime.run({
+      program: 'console.log(`start-${`😀"\\\\\\n`.repeat(100)}`); return null',
+      bindings: [],
+    })
+    expect(result.error).toEqual({ kind: 'output-limit', message: 'outer output exceeded 96 bytes' })
+    expect(result.logs).toHaveLength(1)
+    expect(result.logs[0]?.startsWith('start-')).toBe(true)
+    expect(Buffer.byteLength(JSON.stringify(result.logs), 'utf8')
+      + Buffer.byteLength(JSON.stringify(result.error?.message), 'utf8')).toBeLessThanOrEqual(96)
+  })
+
   it('fails an oversized return value without substituting a string', async () => {
     const { runtime } = await setup({ maxOutputBytes: 64 })
     const result = await runtime.run({ program: 'return "y".repeat(10_000)', bindings: [] })
@@ -304,7 +317,8 @@ describe('WorkerCodeRuntime — budgets and containment (real workers)', () => {
     })
     expect(result.error?.kind).toBe('output-limit')
     expect(result.logs).toContain('a'.repeat(20))
-    expect(result.logs).not.toContain('b'.repeat(100))
+    expect(result.logs[1]?.length).toBeGreaterThan(0)
+    expect('b'.repeat(100).startsWith(result.logs[1] ?? '')).toBe(true)
   }, 15_000)
 })
 
@@ -409,6 +423,32 @@ describe('WorkerCodeRuntime — hostile programs (real workers)', () => {
     expect(result.value).toEqual({ name: 'ToolCallError', toolName: 'bad', message: 'binding resolution must be lossless JSON' })
   })
 
+  it('rejects lossy binding arguments in the worker before invoking the host binding', async () => {
+    const { runtime } = await setup()
+    let calls = 0
+    const result = await runtime.run({
+      program: `
+        const decorated = [1]; Object.defineProperty(decorated, 'extra', { value: true });
+        const values = [new Date(), decorated, () => 1];
+        const failures = [];
+        for (const value of values) {
+          try { await tools.never(value) } catch (error) {
+            failures.push({ typed: error instanceof ToolCallError, name: error.name, toolName: error.toolName, message: error.message });
+          }
+        }
+        return failures;
+      `,
+      bindings: tools({ never: async () => { calls += 1; return null } }),
+    })
+    expect(calls).toBe(0)
+    expect(result.value).toEqual(new Array(3).fill({
+      typed: true,
+      name: 'ToolCallError',
+      toolName: 'never',
+      message: 'binding arguments must be lossless JSON',
+    }))
+  })
+
   it('contains throwing getters while snapshotting binding resolutions', async () => {
     const { runtime } = await setup()
     const result = await runtime.run({

packages/code-runtime/code-runtime-worker/tests/worker-json.spec.ts

@@ -60,12 +60,21 @@ describe('snapshotCodeJsonValue', () => {
     class ExoticArray extends Array<number> {}
     const cyclic: Record<string, unknown> = {}
     cyclic.self = cyclic
+    const decorated = [1]
+    Object.defineProperty(decorated, 'extra', { value: true })
+    const compensatedSparse = new Array(1)
+    Object.defineProperty(compensatedSparse, 'extra', { value: true })
+    const symbolDecorated = [1]
+    Object.defineProperty(symbolDecorated, Symbol('extra'), { value: true })
 
     for (const value of [
       new ExoticObject(),
       new Map([['value', 1]]),
       new ExoticArray(1),
       new Array(1),
+      decorated,
+      compensatedSparse,
+      symbolDecorated,
       cyclic,
       [undefined],
       { value: undefined },