simplifyOptionalChains() — react Function Reference

Architecture documentation for the simplifyOptionalChains() function in minimize.ts from the react codebase.

Function typescript BabelCompiler Optimization calls 1

Entity Profile

BabelCompiler→ Optimization→ simplifyOptionalChains() — react Function Reference

Dependency Diagram

graph TD
  8818efc1_1cb4_0271_6f6d_5b8273969fc6["simplifyOptionalChains()"]
  9c061da8_dbf8_4168_823d_991654a3c55d["minimize.ts"]
  8818efc1_1cb4_0271_6f6d_5b8273969fc6 -->|defined in| 9c061da8_dbf8_4168_823d_991654a3c55d
  7a9af496_ef6a_d9e8_8eaf_1f386f49e4b3["cloneAst()"]
  8818efc1_1cb4_0271_6f6d_5b8273969fc6 -->|calls| 7a9af496_ef6a_d9e8_8eaf_1f386f49e4b3
  style 8818efc1_1cb4_0271_6f6d_5b8273969fc6 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

compiler/packages/snap/src/minimize.ts lines 497–541

function* simplifyOptionalChains(ast: t.File): Generator<t.File> {
  // Count optional expressions
  let optionalCount = 0;
  t.traverseFast(ast, node => {
    if (
      t.isOptionalMemberExpression(node) ||
      t.isOptionalCallExpression(node)
    ) {
      optionalCount++;
    }
  });

  for (let targetIdx = 0; targetIdx < optionalCount; targetIdx++) {
    const cloned = cloneAst(ast);
    let idx = 0;
    let modified = false;

    traverse(cloned, {
      OptionalMemberExpression(path) {
        if (modified) return;
        if (idx === targetIdx) {
          const {object, property, computed} = path.node;
          path.replaceWith(t.memberExpression(object, property, computed));
          modified = true;
        }
        idx++;
      },
      OptionalCallExpression(path) {
        if (modified) return;
        if (idx === targetIdx) {
          const {callee, arguments: args} = path.node;
          if (t.isExpression(callee)) {
            path.replaceWith(t.callExpression(callee, args));
            modified = true;
          }
        }
        idx++;
      },
    });

    if (modified) {
      yield cloned;
    }
  }
}