Function FormatOnEnter

internal/format/api.go:152–189

(ctx context.Context, sourceFile *ast.SourceFile, position int)

}

func FormatOnEnter(ctx context.Context, sourceFile *ast.SourceFile, position int) []core.TextChange {
	line := scanner.GetECMALineOfPosition(sourceFile, position)
	if line == 0 {
		return nil
	}
	// get start position for the previous line
	startPos := int(scanner.GetECMALineStarts(sourceFile)[line-1])
	// After the enter key, the cursor is now at a new line. The new line may or may not contain non-whitespace characters.
	// If the new line has only whitespaces, we won't want to format this line, because that would remove the indentation as
	// trailing whitespaces. So the end of the formatting span should be the later one between:
	//  1. the end of the previous line
	//  2. the last non-whitespace character in the current line
	endOfFormatSpan := scanner.GetECMAEndLinePosition(sourceFile, line)
	for endOfFormatSpan > startPos {
		ch, s := utf8.DecodeRuneInString(sourceFile.Text()[endOfFormatSpan:])
		if s == 0 || stringutil.IsWhiteSpaceSingleLine(ch) { // on multibyte character keep backing up
			endOfFormatSpan--
			continue
		}
		break
	}

	// if the character at the end of the span is a line break, we shouldn't include it, because it indicates we don't want to
	// touch the current line at all. Also, on some OSes the line break consists of two characters (\r\n), we should test if the
	// previous character before the end of format span is line break character as well.
	ch, _ := utf8.DecodeRuneInString(sourceFile.Text()[endOfFormatSpan:])
	if stringutil.IsLineBreak(ch) {
		endOfFormatSpan--
	}

	span := core.NewTextRange(
		startPos,
		// end value is exclusive so add 1 to the result
		endOfFormatSpan+1,
	)

	return FormatSpan(ctx, span, sourceFile, FormatRequestKindFormatOnEnter)
}