no-accumulating-spread

Spreading an accumulator into its replacement copies every value accumulated so far. Repeating the replacement in a loop or reduction callback can make total copying grow quadratically. Instead, you SHOULD use an operation that extends storage without rebuilding the preceding values.

Aliasing can make in-place mutation observably different, so the diagnostic requires a manual rewrite.

1function copy(source: int32[]): int32[] {2    let output: int32[] = [];3    for (const value of source) {4        output = [...output, value];5    }6 7    return output;8}

1function copy(source: int32[]): int32[] {2    let output: int32[] = [];3    for (const value of source) {4        output.push(value);5    }6 7    return output;8}