ralpi/tasks/ralph-loop-fixes/02-fix-spawnpi-print-mode.md

02. Replace spawnPi with --print mode and stdin piping

meta: id: ralph-loop-fixes-02 feature: ralph-loop-fixes priority: P1 depends_on: [] tags: [implementation, utils]

objective:

• Replace spawnPi() so it invokes pi --print with prompt content piped via stdin, instead of using non-existent --no-stream and --prompt flags

deliverables:

• Modified src/utils.ts — spawnPi() function
• Updated src/executor.ts — import and call site for spawnPi

steps:

• Open src/utils.ts and locate spawnPi()
• Replace spawnSync args from ["--no-stream", "--prompt", promptFile, ...] to ["--print"]
• Read the prompt file content and pass it as input to spawnSync
• The input option accepts a string that is piped to the child process stdin
• Keep encoding, timeout, and maxBuffer options as-is
• Update the function signature if needed (no longer needs promptFile path, can take prompt content directly, or read it internally)

tests:

• Manual: Spawn pi with a simple prompt — verify it returns text output and exits cleanly
• Manual: Verify result.stdout contains the pi response text (not NDJSON or event stream)

acceptance_criteria:

• spawnPi() exits with code 0 on successful execution
• result.stdout contains plain text response from pi
• No "Unknown options: --no-stream, --prompt" error

validation:

• Run pi --print with piped input manually to verify behavior
• Check spawnSync call uses ["--print"] args and input option

notes:

• Pi's --print flag runs in non-interactive mode: reads from stdin, writes to stdout, exits
• spawnSync accepts an input option (string) that pipes to child stdin
• Current broken args: ["--no-stream", "--prompt", promptFile]
• The extractTextFromEvent() function can be simplified or removed since --print returns plain text