fix(core): LFO phase, an LFO leak, one RIFF walk, and the copy layer in core

packages/core/package-subpaths.json

@@ -92,6 +92,12 @@
       "types": "./dist/audioFx.d.ts",
       "environments": ["browser", "bun", "node"]
     },
+    "./audio-fx-copy": {
+      "source": "./src/audioFxCopy.ts",
+      "runtime": "./dist/audioFxCopy.js",
+      "types": "./dist/audioFxCopy.d.ts",
+      "environments": ["browser", "bun", "node"]
+    },
     "./audio-fx-eq": {
       "source": "./src/audioFxEq.ts",
       "runtime": "./dist/audioFxEq.js",

packages/core/package.json

@@ -106,6 +106,12 @@
       "import": "./src/audioFx.ts",
       "types": "./src/audioFx.ts"
     },
+    "./audio-fx-copy": {
+      "bun": "./src/audioFxCopy.ts",
+      "node": "./dist/audioFxCopy.js",
+      "import": "./src/audioFxCopy.ts",
+      "types": "./src/audioFxCopy.ts"
+    },
     "./audio-fx-eq": {
       "bun": "./src/audioFxEq.ts",
       "node": "./dist/audioFxEq.js",
@@ -410,6 +416,10 @@
         "import": "./dist/audioFx.js",
         "types": "./dist/audioFx.d.ts"
       },
+      "./audio-fx-copy": {
+        "import": "./dist/audioFxCopy.js",
+        "types": "./dist/audioFxCopy.d.ts"
+      },
       "./audio-fx-eq": {
         "import": "./dist/audioFxEq.js",
         "types": "./dist/audioFxEq.d.ts"

packages/core/scripts/build-audio-fx-runtime.ts

@@ -1,50 +1,13 @@
 /** Build the injectable audio-FX runtime artifact from the canonical runtime. */
 
-import { mkdirSync, writeFileSync } from "node:fs";
-import { dirname, resolve } from "node:path";
-import { fileURLToPath } from "node:url";
-import { buildSync } from "esbuild";
-import { execFileSync } from "node:child_process";
-
-const thisDir = dirname(fileURLToPath(import.meta.url));
-const repoRoot = resolve(thisDir, "..");
-const entry = resolve(repoRoot, "stubs/audio-fx-runtime-entry.ts");
-const generatedDir = resolve(repoRoot, "src/generated");
-const outPath = resolve(generatedDir, "audio-fx-runtime-inline.ts");
-
-const result = buildSync({
-  entryPoints: [entry],
-  bundle: true,
-  write: false,
-  platform: "browser",
-  format: "iife",
-  target: ["es2020"],
-  minify: true,
-  legalComments: "none",
+import { buildInjectedArtifact } from "./buildInjectedArtifact.js";
+
+buildInjectedArtifact({
+  scriptUrl: import.meta.url,
+  entry: "stubs/audio-fx-runtime-entry.ts",
+  out: "audio-fx-runtime-inline.ts",
+  constName: "AUDIO_FX_RUNTIME_IIFE",
+  fnName: "getAudioFxRuntimeScript",
+  what: "audio-FX runtime IIFE",
+  event: "audio_fx_runtime_generated",
 });
-const iife = result.outputFiles[0]?.text ?? "";
-if (!iife) throw new Error("esbuild produced no output for audio-fx-runtime-entry.ts");
-
-mkdirSync(generatedDir, { recursive: true });
-writeFileSync(
-  outPath,
-  [
-    "// AUTO-GENERATED by scripts/build-audio-fx-runtime.ts - do not edit",
-    `const AUDIO_FX_RUNTIME_IIFE: string = ${JSON.stringify(iife)};`,
-    "",
-    "/** Returns the pre-built audio-FX runtime IIFE as a string constant. */",
-    "export function getAudioFxRuntimeScript(): string {",
-    "  return AUDIO_FX_RUNTIME_IIFE;",
-    "}",
-    "",
-  ].join("\n"),
-  "utf8",
-);
-
-try {
-  execFileSync("bun", ["x", "oxfmt", outPath], { stdio: "ignore" });
-} catch {
-  // Formatting is best effort when the generator runs in a minimal environment.
-}
-
-console.log(JSON.stringify({ event: "audio_fx_runtime_generated", outPath, bytes: iife.length }));

packages/core/scripts/build-position-edits-render.ts

@@ -1,52 +1,13 @@
 /** Build the injectable position-edits render artifact from the canonical runtime. */
 
-import { mkdirSync, writeFileSync } from "node:fs";
-import { dirname, resolve } from "node:path";
-import { fileURLToPath } from "node:url";
-import { buildSync } from "esbuild";
-import { execFileSync } from "node:child_process";
-
-const thisDir = dirname(fileURLToPath(import.meta.url));
-const repoRoot = resolve(thisDir, "..");
-const entry = resolve(repoRoot, "stubs/position-edits-render-entry.ts");
-const generatedDir = resolve(repoRoot, "src/generated");
-const outPath = resolve(generatedDir, "position-edits-render-inline.ts");
-
-const result = buildSync({
-  entryPoints: [entry],
-  bundle: true,
-  write: false,
-  platform: "browser",
-  format: "iife",
-  target: ["es2020"],
-  minify: true,
-  legalComments: "none",
+import { buildInjectedArtifact } from "./buildInjectedArtifact.js";
+
+buildInjectedArtifact({
+  scriptUrl: import.meta.url,
+  entry: "stubs/position-edits-render-entry.ts",
+  out: "position-edits-render-inline.ts",
+  constName: "POSITION_EDITS_RENDER_IIFE",
+  fnName: "getPositionEditsRenderScript",
+  what: "position-edits render IIFE",
+  event: "position_edits_render_generated",
 });
-const iife = result.outputFiles[0]?.text ?? "";
-if (!iife) throw new Error("esbuild produced no output for position-edits-render-entry.ts");
-
-mkdirSync(generatedDir, { recursive: true });
-writeFileSync(
-  outPath,
-  [
-    "// AUTO-GENERATED by scripts/build-position-edits-render.ts - do not edit",
-    `const POSITION_EDITS_RENDER_IIFE: string = ${JSON.stringify(iife)};`,
-    "",
-    "/** Returns the pre-built position-edits render IIFE as a string constant. */",
-    "export function getPositionEditsRenderScript(): string {",
-    "  return POSITION_EDITS_RENDER_IIFE;",
-    "}",
-    "",
-  ].join("\n"),
-  "utf8",
-);
-
-try {
-  execFileSync("bun", ["x", "oxfmt", outPath], { stdio: "ignore" });
-} catch {
-  // Formatting is best effort when the generator runs in a minimal environment.
-}
-
-console.log(
-  JSON.stringify({ event: "position_edits_render_generated", outPath, bytes: iife.length }),
-);

packages/core/scripts/buildInjectedArtifact.ts

@@ -0,0 +1,78 @@
+/**
+ * Bundle a stub entry into an injectable IIFE, wrapped as a TypeScript constant.
+ *
+ * Two artifacts are built this way — the audio-FX runtime and the position-edits
+ * render — and the engine injects both into the headless browser as a script tag.
+ * They were two copies of this file differing in five names, which is a poor
+ * place for a divergence to hide: whichever copy stopped being edited would go on
+ * producing a subtly different artifact with nothing to say so.
+ */
+
+import { execFileSync } from "node:child_process";
+import { mkdirSync, writeFileSync } from "node:fs";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+import { buildSync } from "esbuild";
+
+export interface InjectedArtifact {
+  /** The build script's own `import.meta.url`, so paths resolve beside it. */
+  scriptUrl: string;
+  /** Entry stub, relative to the package root. */
+  entry: string;
+  /** Output file name inside `src/generated`. */
+  out: string;
+  /** SCREAMING_CASE name for the string constant holding the IIFE. */
+  constName: string;
+  /** The accessor the rest of the codebase imports. */
+  fnName: string;
+  /** What that accessor returns, for its doc comment: "the pre-built X". */
+  what: string;
+  /** Structured log event name. */
+  event: string;
+}
+
+export function buildInjectedArtifact(spec: InjectedArtifact): void {
+  const scriptDir = dirname(fileURLToPath(spec.scriptUrl));
+  const scriptName = spec.scriptUrl.split("/").pop() ?? "";
+  const repoRoot = resolve(scriptDir, "..");
+  const entry = resolve(repoRoot, spec.entry);
+  const generatedDir = resolve(repoRoot, "src/generated");
+  const outPath = resolve(generatedDir, spec.out);
+
+  const result = buildSync({
+    entryPoints: [entry],
+    bundle: true,
+    write: false,
+    platform: "browser",
+    format: "iife",
+    target: ["es2020"],
+    minify: true,
+    legalComments: "none",
+  });
+  const iife = result.outputFiles[0]?.text ?? "";
+  if (!iife) throw new Error(`esbuild produced no output for ${spec.entry.split("/").pop()}`);
+
+  mkdirSync(generatedDir, { recursive: true });
+  writeFileSync(
+    outPath,
+    [
+      `// AUTO-GENERATED by scripts/${scriptName} - do not edit`,
+      `const ${spec.constName}: string = ${JSON.stringify(iife)};`,
+      "",
+      `/** Returns the pre-built ${spec.what} as a string constant. */`,
+      `export function ${spec.fnName}(): string {`,
+      `  return ${spec.constName};`,
+      "}",
+      "",
+    ].join("\n"),
+    "utf8",
+  );
+
+  try {
+    execFileSync("bun", ["x", "oxfmt", outPath], { stdio: "ignore" });
+  } catch {
+    // Formatting is best effort when the generator runs in a minimal environment.
+  }
+
+  console.log(JSON.stringify({ event: spec.event, outPath, bytes: iife.length }));
+}