Method flattenBlocks

compiler/companion/src/JSXProcessor.ts:1207–1234

* Merge any added blocks into the statements list

(
    node: ts.Node,
    previousStatements: ts.NodeArray<ts.Node> | ts.Node[],
    newStatements: ts.Statement[],
  )

   * Merge any added blocks into the statements list
   */
  private flattenBlocks(
    node: ts.Node,
    previousStatements: ts.NodeArray<ts.Node> | ts.Node[],
    newStatements: ts.Statement[],
  ): ts.Statement[] {
    if (newStatements.length !== previousStatements.length) {
      this.onError(
        node,
        `Invalid output statements, had length ${previousStatements.length} new length ${newStatements.length}`,
      );
    }

    const out: ts.Statement[] = [];

    for (let i = 0; i < previousStatements.length; i++) {
      const oldStatement = previousStatements[i];
      const newStatement = newStatements[i];

      if (ts.isBlock(newStatement) && !ts.isBlock(oldStatement)) {
        // We created a block, merge its content into the statements
        out.push(...newStatement.statements);
      } else {
        out.push(newStatement);
      }
    }

    return out;
  }

  private doUpdateSourceFileNode(
    node: ts.SourceFile,