Add unified build script with selective build flags

Replaces individual build:js, build:types, and build:externals scripts with
a single build script that supports --js, --types, and --externals flags.

Running without flags executes full build (clean + all steps + fix:exports).
With flags, only specified build steps run without clean or fix:exports.

Author: jdalton

package.json

@@ -715,19 +715,14 @@
   },
   "sideEffects": false,
   "scripts": {
-    "build": "pnpm run clean && pnpm run build:js && pnpm run build:types && pnpm run build:externals && pnpm run fix:exports",
-    "build:js": "node scripts/build-js.mjs",
-    "build:types": "tsgo --project tsconfig.dts.json --declaration --emitDeclarationOnly",
-    "build:externals": "node scripts/build-externals.mjs",
+    "build": "node scripts/build.mjs",
     "build:watch": "node scripts/build-js.mjs --watch",
     "check": "node scripts/check.mjs",
     "claude": "node scripts/claude.mjs",
     "clean": "del-cli dist '**/*.tsbuildinfo'",
     "cover": "node scripts/cover.mjs",
     "dev": "pnpm run build:watch",
     "fix": "node scripts/fix.mjs",
-    "fix:exports": "node scripts/fix-commonjs-exports.mjs",
-    "fix:imports": "node scripts/fix-default-imports.mjs",
     "lint": "biome check .",
     "lint-ci": "pnpm run lint",
     "prepare": "husky",

scripts/build.mjs

@@ -0,0 +1,107 @@
+/**
+ * @fileoverview Build script with selective build step flags.
+ */
+
+import { spawn } from 'node:child_process'
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
+
+import { printError, printHeader } from './utils/cli-helpers.mjs'
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url))
+const rootPath = path.join(__dirname, '..')
+
+/**
+ * Run a command and return a promise that resolves when it completes.
+ */
+function runCommand(command, args, label) {
+  return new Promise((resolve, reject) => {
+    printHeader(label)
+    const child = spawn(command, args, {
+      stdio: 'inherit',
+      cwd: rootPath,
+      ...(process.platform === 'win32' && { shell: true }),
+    })
+
+    child.on('exit', code => {
+      if (code === 0) {
+        resolve()
+      } else {
+        reject(new Error(`${label} exited with code ${code}`))
+      }
+    })
+
+    child.on('error', error => {
+      printError(`${label} failed: ${error.message}`)
+      reject(error)
+    })
+  })
+}
+
+// Parse command line flags
+const args = process.argv.slice(2)
+const flags = {
+  js: args.includes('--js'),
+  types: args.includes('--types'),
+  externals: args.includes('--externals'),
+}
+
+// If no flags specified, run all steps
+const runAll = !flags.js && !flags.types && !flags.externals
+
+// Run build steps
+async function main() {
+  try {
+    // Clean first if running full build
+    if (runAll) {
+      await runCommand(
+        'pnpm',
+        ['run', 'clean'],
+        'Cleaning Build Artifacts',
+      )
+    }
+
+    // Build JS
+    if (runAll || flags.js) {
+      await runCommand(
+        'node',
+        [path.join(__dirname, 'build-js.mjs')],
+        'Building JavaScript',
+      )
+    }
+
+    // Build types
+    if (runAll || flags.types) {
+      await runCommand(
+        'pnpm',
+        ['exec', 'tsgo', '--project', 'tsconfig.dts.json', '--declaration', '--emitDeclarationOnly'],
+        'Building Types',
+      )
+    }
+
+    // Build externals
+    if (runAll || flags.externals) {
+      await runCommand(
+        'node',
+        [path.join(__dirname, 'build-externals.mjs')],
+        'Building Externals',
+      )
+    }
+
+    // Fix exports at the end if running full build
+    if (runAll) {
+      await runCommand(
+        'pnpm',
+        ['run', 'fix:exports'],
+        'Fixing CommonJS Exports',
+      )
+    }
+
+    process.exitCode = 0
+  } catch (error) {
+    printError(`Build script failed: ${error.message}`)
+    process.exitCode = 1
+  }
+}
+
+main()