Visitor Class — react Architecture

Source Code

compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/PruneInitializationDependencies.ts lines 65–212

class Visitor extends ReactiveFunctionVisitor<CreateUpdate> {
  map: KindMap = new Map();
  aliases: DisjointSet<IdentifierId>;
  paths: Map<IdentifierId, Map<PropertyLiteral, IdentifierId>>;
  env: Environment;

  constructor(
    env: Environment,
    aliases: DisjointSet<IdentifierId>,
    paths: Map<IdentifierId, Map<PropertyLiteral, IdentifierId>>,
  ) {
    super();
    this.aliases = aliases;
    this.paths = paths;
    this.env = env;
  }

  join(values: Array<CreateUpdate>): CreateUpdate {
    function join2(l: CreateUpdate, r: CreateUpdate): CreateUpdate {
      if (l === 'Update' || r === 'Update') {
        return 'Update';
      } else if (l === 'Create' || r === 'Create') {
        return 'Create';
      } else if (l === 'Unknown' || r === 'Unknown') {
        return 'Unknown';
      }
      assertExhaustive(r, `Unhandled variable kind ${r}`);
    }
    return values.reduce(join2, 'Unknown');
  }

  isCreateOnlyHook(id: Identifier): boolean {
    return isUseStateType(id) || isUseRefType(id);
  }

  override visitPlace(
    _: InstructionId,
    place: Place,
    state: CreateUpdate,
  ): void {
    this.map.set(
      place.identifier.id,
      this.join([state, this.map.get(place.identifier.id) ?? 'Unknown']),
    );
  }

  override visitBlock(block: ReactiveBlock, state: CreateUpdate): void {
    super.visitBlock([...block].reverse(), state);
  }

  override visitInstruction(instruction: ReactiveInstruction): void {
    const state = this.join(
      [...eachInstructionLValue(instruction)].map(
        operand => this.map.get(operand.identifier.id) ?? 'Unknown',
      ),
    );

    const visitCallOrMethodNonArgs = (): void => {
      switch (instruction.value.kind) {
        case 'CallExpression': {
          this.visitPlace(instruction.id, instruction.value.callee, state);
          break;
        }
        case 'MethodCall': {
          this.visitPlace(instruction.id, instruction.value.property, state);
          this.visitPlace(instruction.id, instruction.value.receiver, state);
          break;
        }
      }
    };

    const isHook = (): boolean => {
      let callee = null;
      switch (instruction.value.kind) {
        case 'CallExpression': {
          callee = instruction.value.callee.identifier;
          break;
        }
        case 'MethodCall': {
          callee = instruction.value.property.identifier;
          break;