Function rnEventEdges

src/resolution/callback-synthesizer.ts:1049–1201

(ctx: ResolutionContext)

const RN_NATIVE_SENDEVENT_RE = /\bsendEvent\s*\([^;{}]*?"([^"]+)"/g;

function rnEventEdges(ctx: ResolutionContext): Edge[] {
  // Native dispatchers (source = the native method whose body sends the
  // event) and JS handlers (target = the function/method registered as
  // the listener) keyed by event name.
  const nativeDispatchersByEvent = new Map<string, Set<string>>();
  const jsHandlersByEvent = new Map<string, Map<string, string>>();

  for (const file of ctx.getAllFiles()) {
    const content = ctx.readFile(file);
    if (!content) continue;

    const nodesInFile = ctx.getNodesInFile(file);
    const lineOf = (idx: number) => content.slice(0, idx).split('\n').length;
    const addDispatcher = (event: string, line: number) => {
      const disp = enclosingFn(nodesInFile, line);
      if (!disp) return;
      const set = nativeDispatchersByEvent.get(event) ?? new Set<string>();
      set.add(disp.id);
      nativeDispatchersByEvent.set(event, set);
    };

    // ObjC side: `sendEventWithName:@"X"` only fires inside `.m`/`.mm`
    // files (RCTEventEmitter subclasses).
    if (file.endsWith('.m') || file.endsWith('.mm')) {
      RN_OBJC_SEND_RE.lastIndex = 0;
      let m: RegExpExecArray | null;
      while ((m = RN_OBJC_SEND_RE.exec(content))) {
        if (m[1]) addDispatcher(m[1], lineOf(m.index));
      }
    }

    // Swift side: same RCTEventEmitter method, parens/named-args syntax.
    if (file.endsWith('.swift')) {
      RN_SWIFT_SEND_RE.lastIndex = 0;
      let m: RegExpExecArray | null;
      while ((m = RN_SWIFT_SEND_RE.exec(content))) {
        if (m[1]) addDispatcher(m[1], lineOf(m.index));
      }
      RN_NATIVE_SENDEVENT_RE.lastIndex = 0;
      while ((m = RN_NATIVE_SENDEVENT_RE.exec(content))) {
        if (m[1]) addDispatcher(m[1], lineOf(m.index));
      }
    }

    // JVM side: `.emit("X", …)` in Java/Kotlin, plus the common
    // `sendEvent(ctx, "X", body)` wrapper. (We pattern-match anywhere in the
    // file; the JS in-language path uses a separate emitter object pattern and
    // is already handled by eventEmitterEdges.)
    if (file.endsWith('.java') || file.endsWith('.kt')) {
      let m: RegExpExecArray | null;
      RN_JVM_EMIT_RE.lastIndex = 0;
      while ((m = RN_JVM_EMIT_RE.exec(content))) {
        if (m[1]) addDispatcher(m[1], lineOf(m.index));
      }
      RN_NATIVE_SENDEVENT_RE.lastIndex = 0;
      while ((m = RN_NATIVE_SENDEVENT_RE.exec(content))) {
        if (m[1]) addDispatcher(m[1], lineOf(m.index));
      }