spawn-bin.ts

/**
 * Windows-safe resolution + spawn for gstack's bash bins. Two Windows-only
 * bugs made every hook subprocess a silent no-op; both are fixed here so all
 * call sites are covered at once.
 *
 * 1. `new URL(import.meta.url).pathname` yields `/C:/Users/...`; path.resolve
 *    then rebases it onto the drive root as `C:\C:\Users\...`. fileURLToPath
 *    is the correct conversion. (ENOENT before the bin ever ran.)
 * 2. `bin/gstack-*` are extensionless bash scripts. Windows has no shebang
 *    support, so they must be handed to bash explicitly.
 *
 * Also home to runExternal: the contained runner for EXTERNAL executables
 * (third-party binaries a hook hands data to; see its doc comment). Unlike
 * runBin it refuses win32, because its guarantee is process-group containment.
 */
import * as fs from 'fs';
import * as path from 'path';
import { fileURLToPath } from 'url';
import { spawn, spawnSync, type SpawnSyncOptions } from 'child_process';

// Forward slashes on purpose: Bun's spawnSync on Windows returns ENOENT for a
// backslash exe path containing spaces.
const GIT_BASH = 'C:/Program Files/Git/bin/bash.exe';
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