Function appendCompileAndEvalInput

src/repl.ts:508–664

* Evaluate the code snippet. * * Append it to virtual .ts file, compile, handle compiler errors, compute a diff of the JS, and eval any code that * appears as "added" in the diff.

(options: {
  service: Service;
  state: EvalState;
  input: string;
  wrappedErr?: unknown;
  /** Enable top-level await but only if the TSNode service allows it. */
  enableTopLevelAwait?: boolean;
  context: Context | undefined;
  /**
   * Added so that `evalCode` can be guaranteed *not* to trigger the `isCompletion`
   * codepath.  However, the `isCompletion` logic is ancient and maybe should be removed entirely.
   * Nobody's looked at it in a long time.
   */
  overrideIsCompletion?: boolean;
})

 * appears as "added" in the diff.
 */
function appendCompileAndEvalInput(options: {
  service: Service;
  state: EvalState;
  input: string;
  wrappedErr?: unknown;
  /** Enable top-level await but only if the TSNode service allows it. */
  enableTopLevelAwait?: boolean;
  context: Context | undefined;
  /**
   * Added so that `evalCode` can be guaranteed *not* to trigger the `isCompletion`
   * codepath.  However, the `isCompletion` logic is ancient and maybe should be removed entirely.
   * Nobody's looked at it in a long time.
   */
  overrideIsCompletion?: boolean;
}): AppendCompileAndEvalInputResult {
  const {
    service,
    state,
    wrappedErr,
    enableTopLevelAwait = false,
    context,
    overrideIsCompletion,
  } = options;
  let { input } = options;

  // It's confusing for `{ a: 1 }` to be interpreted as a block statement
  // rather than an object literal. So, we first try to wrap it in
  // parentheses, so that it will be interpreted as an expression.
  // Based on https://github.com/nodejs/node/blob/c2e6822153bad023ab7ebd30a6117dcc049e475c/lib/repl.js#L413-L422
  let wrappedCmd = false;
  if (!wrappedErr && /^\s*{/.test(input) && !/;\s*$/.test(input)) {
    input = `(${input.trim()})\n`;
    wrappedCmd = true;
  }

  const lines = state.lines;
  const isCompletion = overrideIsCompletion ?? !/\n$/.test(input);
  const undo = appendToEvalState(state, input);
  let output: string;

  // Based on https://github.com/nodejs/node/blob/92573721c7cff104ccb82b6ed3e8aa69c4b27510/lib/repl.js#L457-L461
  function adjustUseStrict(code: string) {
    // "void 0" keeps the repl from returning "use strict" as the result
    // value for statements and declarations that don't return a value.
    return code.replace(/^"use strict";/, '"use strict"; void 0;');
  }

  try {
    output = service.compile(state.input, state.path, -lines);
  } catch (err) {
    undo();

    if (wrappedCmd) {
      if (err instanceof TSError && err.diagnosticCodes[0] === 2339) {
        // Ensure consistent and more sane behavior between { a: 1 }['b'] and ({ a: 1 }['b'])
        throw err;
      }
      // Unwrap and try again