refactor(runtime): compose consumers over fs and subprocess

packages/fs/fs-local/tests/filesystem.spec.ts

@@ -10,6 +10,7 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import { mkdir, mkdtemp, readFile, realpath, rm, stat, symlink, unlink, utimes, writeFile } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
+import { pathToFileURL } from 'node:url'
 import { Context } from 'cordis'
 import { LocalFileSystem } from '@deepseek-ai/dsh-fs-local'
 import { FsVersion } from '@deepseek-ai/dsh-fs'
@@ -85,6 +86,20 @@ describe('resolve', () => {
 
     await expect(pending).rejects.toMatchObject({ code: 'FS_ABORTED' })
   })
+
+  it('projects process paths, file URLs, and canonical containment', async () => {
+    await mkdir(join(dir, 'nested'))
+    await writeFile(join(dir, 'nested', 'file.txt'), 'text')
+    const root = await fs.resolve('.')
+    const child = await fs.resolve('nested/file.txt')
+    const outside = await fs.resolve('..')
+
+    expect(fs.processPath(child)).toBe(await realpath(join(dir, 'nested', 'file.txt')))
+    expect(fs.fileUrl(child)).toBe(pathToFileURL(await realpath(join(dir, 'nested', 'file.txt'))).href)
+    expect(fs.contains(root, root)).toBe(true)
+    expect(fs.contains(root, child)).toBe(true)
+    expect(fs.contains(root, outside)).toBe(false)
+  })
 })
 
 describe('stat', () => {
@@ -203,6 +218,15 @@ describe('readText / streamText', () => {
     expect(await fs.readText(await fs.resolve('a.txt'))).toBe('one\ntwo\nthree')
   })
 
+  it('reads complete text through the stable byte bound', async () => {
+    await writeFile(join(dir, 'bounded.txt'), '€abc')
+    const target = await fs.resolve('bounded.txt')
+    expect(await fs.readTextBounded(target, 6)).toBe('€abc')
+    await expect(fs.readTextBounded(target, 5)).rejects.toThrow('exceeds the 5-byte limit')
+    await expect(fs.readTextBounded(target, 0)).rejects.toThrow('positive safe integer')
+    await expect(fs.readTextBounded(target, 6, AbortSignal.abort())).rejects.toMatchObject({ code: 'FS_ABORTED' })
+  })
+
   it('streams the same text', async () => {
     await writeFile(join(dir, 'a.txt'), 'one\ntwo\nthree')
     const target = await fs.resolve('a.txt')

packages/fs/fs-local/tests/fsio.spec.ts

@@ -5,7 +5,7 @@
  * policy and lives in `dsh-fs-policy`, so it is not tested here.
  */
 
-import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import { chmod, mkdtemp, readFile, rename, rm, stat, symlink, unlink, writeFile, mkdir, readdir, realpath } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
@@ -17,6 +17,7 @@ import {
   probeNoFollow,
   readForEdit,
   readWholeText,
+  readWholeTextBounded,
   resolveLocalTarget,
   restoreLineEndings,
   streamWholeText,
@@ -316,6 +317,66 @@ describe('readWholeText', () => {
   })
 })
 
+describe('readWholeTextBounded', () => {
+  it('rejects non-files, binary text, and initial oversize without a full read', async () => {
+    await expect(readWholeTextBounded(localTarget(dir), 10)).rejects.toMatchObject({ code: 'FS_NOT_REGULAR_FILE' })
+    await writeFile(join(dir, 'large'), '12345')
+    await expect(readWholeTextBounded(localTarget(join(dir, 'large')), 4)).rejects.toThrow('exceeds the 4-byte limit')
+    await writeFile(join(dir, 'binary'), Buffer.from([0x61, 0x00, 0x62]))
+    await expect(readWholeTextBounded(localTarget(join(dir, 'binary')), 3)).rejects.toMatchObject({ code: 'FS_NOT_TEXT' })
+  })
+
+  it('detects growth past the bound on the same open handle', async () => {
+    const close = vi.fn(async () => {})
+    const read = vi.fn(async (buffer: Buffer, offset: number, length: number, position: number) => {
+      const bytes = position === 0 ? Buffer.from('abc') : Buffer.from('d')
+      bytes.copy(buffer, offset, 0, Math.min(length, bytes.length))
+      return { bytesRead: Math.min(length, bytes.length), buffer }
+    })
+    vi.resetModules()
+    vi.doMock('node:fs/promises', async (importOriginal) => {
+      const actual = await importOriginal<typeof import('node:fs/promises')>()
+      return {
+        ...actual,
+        open: async () => ({
+          stat: async () => ({ isFile: () => true, size: 3 }),
+          read,
+          close,
+        }),
+      }
+    })
+    try {
+      const isolated = await import('../src/fsio.ts')
+      await expect(isolated.readWholeTextBounded(localTarget('/virtual/growing'), 3))
+        .rejects.toThrow('grew past the 3-byte limit')
+      expect(close).toHaveBeenCalledOnce()
+    } finally {
+      vi.doUnmock('node:fs/promises')
+      vi.resetModules()
+    }
+  })
+
+  it('translates permission and generic open failures', async () => {
+    const failure: { current: Error & { code?: string } } = { current: Object.assign(new Error('denied'), { code: 'EACCES' }) }
+    vi.resetModules()
+    vi.doMock('node:fs/promises', async (importOriginal) => {
+      const actual = await importOriginal<typeof import('node:fs/promises')>()
+      return { ...actual, open: async () => { throw failure.current } }
+    })
+    try {
+      const isolated = await import('../src/fsio.ts')
+      await expect(isolated.readWholeTextBounded(localTarget('/virtual/denied'), 3))
+        .rejects.toMatchObject({ code: 'FS_PERMISSION_DENIED' })
+      failure.current = new Error('open broke')
+      await expect(isolated.readWholeTextBounded(localTarget('/virtual/broken'), 3))
+        .rejects.toMatchObject({ code: 'FS_IO_ERROR' })
+    } finally {
+      vi.doUnmock('node:fs/promises')
+      vi.resetModules()
+    }
+  })
+})
+
 describe('streamWholeText', () => {
   it('streams the whole file as decoded text', async () => {
     const file = join(dir, 'a.txt')