Add a Pi scenario driver and watch items read through a shell variable (refs #3748)

packages/skill/plugins/claude-code/hooks/register.ts

@@ -615,12 +615,38 @@ export function nodespaceInvocations(command: string): string[][] {
   endWord()
 
   const invocations: string[][] = []
+  /** What earlier plain assignments in the line set: `id=<uuid>; nodespace node context $id`. */
+  const assigned = new Map<string, string>()
+  const expand = (token: string): string => {
+    const name = /^\$(?:\{([A-Za-z_][A-Za-z0-9_]*)\}|([A-Za-z_][A-Za-z0-9_]*))$/.exec(token)
+
+    return assigned.get(name?.[1] ?? name?.[2] ?? '') ?? token
+  }
 
   for (const segment of segments) {
     const start = segment.findIndex(token => !/^[A-Za-z_][A-Za-z0-9_]*=/.test(token))
     const head = segment[start] ?? ''
 
-    if (start < 0 || (head !== 'nodespace' && !head.endsWith('/nodespace'))) {
+    // A segment of assignments alone sets variables for what follows; one in
+    // front of a command is scoped to that command. A value that is still
+    // an expansion (`$(...)`, a backtick, a name not set here) is unknown:
+    // the name is forgotten rather than kept as that text.
+    if (start < 0) {
+      for (const token of segment) {
+        const split = token.indexOf('=')
+        const value = expand(token.slice(split + 1))
+
+        if (/[$`]/.test(value)) {
+          assigned.delete(token.slice(0, split))
+        } else {
+          assigned.set(token.slice(0, split), value)
+        }
+      }
+
+      continue
+    }
+
+    if (head !== 'nodespace' && !head.endsWith('/nodespace')) {
       continue
     }
 
@@ -632,7 +658,7 @@ export function nodespaceInvocations(command: string): string[][] {
       if (token === '--database' || token === '--socket') {
         i += 1
       } else if (token !== '--json' && !/^--(database|socket)=/.test(token)) {
-        words.push(token)
+        words.push(expand(token))
       }
     }
 

packages/skill/plugins/claude-code/tests/register.test.ts

@@ -1168,6 +1168,23 @@ describe('reading the shell line and the remote', () => {
     expect(nodespaceInvocations('git status')).toEqual([])
   })
 
+  test('reads a variable set earlier in the line as what it was set to, and no further', () => {
+    expect(nodespaceInvocations('id=t1; nodespace node context $id | head')).toEqual([['node', 'context', 't1']])
+    expect(nodespaceInvocations('ID=t1 && nodespace node context "${ID}"')).toEqual([['node', 'context', 't1']])
+    // The last assignment wins, and one variable can be set from another.
+    expect(nodespaceInvocations('id=t1; id=t2; nodespace node context $id')).toEqual([['node', 'context', 't2']])
+    expect(nodespaceInvocations('a=t1; b=$a; nodespace node context $b')).toEqual([['node', 'context', 't1']])
+    // What cannot be known stays as written: a prefix assignment is scoped to its own command,
+    // a command's output and `export` are not read, and a name never set here is not guessed.
+    expect(nodespaceInvocations('id=t1 nodespace node context $id')).toEqual([['node', 'context', '$id']])
+    expect(nodespaceInvocations('export id=t1; nodespace node context $id')).toEqual([['node', 'context', '$id']])
+    expect(nodespaceInvocations('nodespace node context $id')).toEqual([['node', 'context', '$id']])
+    expect(nodespaceInvocations('id=$(nodespace node create x); nodespace node context $id')).toEqual([
+      ['node', 'create', 'x'],
+      ['node', 'context', '$id'],
+    ])
+  })
+
   test("the lookup names the checkout's own remote when it is none of the common spellings", () => {
     const remote = 'ssh://git@gitlab.example.com:2222/group/repo.git\n'
     const spellings = remoteSpellings(httpsRemote(remote) ?? '', remote)

packages/skill/plugins/shared/nodespace-session.ts

@@ -428,12 +428,38 @@ export function nodespaceInvocations(command: string): string[][] {
   endWord()
 
   const invocations: string[][] = []
+  /** What earlier plain assignments in the line set: `id=<uuid>; nodespace node context $id`. */
+  const assigned = new Map<string, string>()
+  const expand = (token: string): string => {
+    const name = /^\$(?:\{([A-Za-z_][A-Za-z0-9_]*)\}|([A-Za-z_][A-Za-z0-9_]*))$/.exec(token)
+
+    return assigned.get(name?.[1] ?? name?.[2] ?? '') ?? token
+  }
 
   for (const segment of segments) {
     const start = segment.findIndex(token => !/^[A-Za-z_][A-Za-z0-9_]*=/.test(token))
     const head = segment[start] ?? ''
 
-    if (start < 0 || (head !== 'nodespace' && !head.endsWith('/nodespace'))) {
+    // A segment of assignments alone sets variables for what follows; one in
+    // front of a command is scoped to that command. A value that is still
+    // an expansion (`$(...)`, a backtick, a name not set here) is unknown:
+    // the name is forgotten rather than kept as that text.
+    if (start < 0) {
+      for (const token of segment) {
+        const split = token.indexOf('=')
+        const value = expand(token.slice(split + 1))
+
+        if (/[$`]/.test(value)) {
+          assigned.delete(token.slice(0, split))
+        } else {
+          assigned.set(token.slice(0, split), value)
+        }
+      }
+
+      continue
+    }
+
+    if (head !== 'nodespace' && !head.endsWith('/nodespace')) {
       continue
     }
 
@@ -445,7 +471,7 @@ export function nodespaceInvocations(command: string): string[][] {
       if (token === '--database' || token === '--socket') {
         i += 1
       } else if (token !== '--json' && !/^--(database|socket)=/.test(token)) {
-        words.push(token)
+        words.push(expand(token))
       }
     }
 

packages/skill/src/tests/plugin-session.test.ts

@@ -5,7 +5,7 @@
 import { describe, it, expect, afterEach, beforeEach, vi } from 'vitest';
 import nodespacePi from '../../plugins/pi/index';
 import { NodeSpace as nodespaceOpenCode } from '../../plugins/opencode/nodespace';
-import { createSession, httpsRemote } from '../../plugins/shared/nodespace-session';
+import { createSession, httpsRemote, nodespaceInvocations } from '../../plugins/shared/nodespace-session';
 import type { Host } from '../../plugins/shared/nodespace-session';
 import { CONSENT_RULES, ORIENTATION } from '../shipped-text.js';
 
@@ -403,6 +403,39 @@ describe('a session, whichever harness it runs in', () => {
     expect(w.calls).toHaveLength(before + 1);
   });
 
+  it('watches an item the context read names through a variable set earlier in the line', async () => {
+    const w = world();
+    const session = createSession(hostOf(w), 60_000);
+    await session.start('/work/widgets', { sessionId: 'ses_1' });
+    await session.afterTool('id=t1; nodespace node context $id | head -40', '');
+    expect(commands(w).slice(-1)).toEqual(['node context t1']);
+
+    await session.afterTool('ID=t1 && nodespace node context "${ID}"', '');
+    expect(commands(w).slice(-1)).toEqual(['node context t1']);
+
+    w.item = { id: 't1', version: 4, title: 'Add the gauge', properties: { status: 'done' } };
+    w.contextVersion = 'c2';
+    w.now += 61_000;
+    expect(await session.beforeTool()).toMatchObject({ deny: expect.stringContaining('changed under it') });
+  });
+
+  it('reads a variable set earlier in the line as what it was set to, and no further', () => {
+    expect(nodespaceInvocations('id=t1; nodespace node context $id | head')).toEqual([['node', 'context', 't1']])
+    expect(nodespaceInvocations('ID=t1 && nodespace node context "${ID}"')).toEqual([['node', 'context', 't1']])
+    // The last assignment wins, and one variable can be set from another.
+    expect(nodespaceInvocations('id=t1; id=t2; nodespace node context $id')).toEqual([['node', 'context', 't2']])
+    expect(nodespaceInvocations('a=t1; b=$a; nodespace node context $b')).toEqual([['node', 'context', 't1']])
+    // What cannot be known stays as written: a prefix assignment is scoped to its own command,
+    // a command's output and `export` are not read, and a name never set here is not guessed.
+    expect(nodespaceInvocations('id=t1 nodespace node context $id')).toEqual([['node', 'context', '$id']])
+    expect(nodespaceInvocations('export id=t1; nodespace node context $id')).toEqual([['node', 'context', '$id']])
+    expect(nodespaceInvocations('nodespace node context $id')).toEqual([['node', 'context', '$id']])
+    expect(nodespaceInvocations('id=$(nodespace node create x); nodespace node context $id')).toEqual([
+      ['node', 'create', 'x'],
+      ['node', 'context', '$id'],
+    ])
+  });
+
   // A harness whose hooks are one process per event (Codex) keeps the state in
   // a file: a session rebuilt from its snapshot is the session it was.
   it('behaves the same when each call runs on a session rebuilt from the last one\'s snapshot', async () => {

scripts/eval/harness/pi.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, test } from "bun:test";
+import { records } from "./pi.ts";
+
+/** A byte stream that delivers `chunks` as they are given, however they cut the text. */
+async function* chunked(...chunks: string[]): AsyncGenerator<Uint8Array> {
+  const encoder = new TextEncoder();
+
+  for (const chunk of chunks) {
+    yield encoder.encode(chunk);
+  }
+}
+
+async function all(stream: AsyncIterable<Uint8Array>): Promise<string[]> {
+  const out: string[] = [];
+
+  for await (const line of records(stream)) {
+    out.push(line);
+  }
+
+  return out;
+}
+
+describe("Pi's JSONL framing", () => {
+  test("splits on LF only, across chunks, and strips a CR", async () => {
+    expect(await all(chunked('{"a":1}\r\n{"b"', ':2}\n{"c":3}\n'))).toEqual(['{"a":1}', '{"b":2}', '{"c":3}']);
+  });
+
+  test("keeps a Unicode line or paragraph separator inside its record", async () => {
+    const record = JSON.stringify({ text: "one
two
three" });
+
+    expect(await all(chunked(`${record}\n`))).toEqual([record]);
+  });
+
+  test("keeps a multi-byte character cut between chunks", async () => {
+    const bytes = new TextEncoder().encode('{"t":"é"}\n');
+    const cut = bytes.indexOf(0xc3) + 1;
+    const stream = (async function* () {
+      yield bytes.slice(0, cut);
+      yield bytes.slice(cut);
+    })();
+
+    expect(await all(stream)).toEqual(['{"t":"é"}']);
+  });
+
+  test("yields a last record that has no newline", async () => {
+    expect(await all(chunked('{"a":1}\n{"b":2}'))).toEqual(['{"a":1}', '{"b":2}']);
+  });
+});