codeFrame() — astro Function Reference

Architecture documentation for the codeFrame() function in printer.ts from the astro codebase.

Function typescript CoreAstro RenderingEngine

Entity Profile

CoreAstro→ RenderingEngine→ codeFrame() — astro Function Reference

Dependency Diagram

graph TD
  177904c0_fd11_5ea7_1df2_8e57b83ea2db["codeFrame()"]
  7d34d289_ea0e_ec1c_780b_4c297e3a4f60["printer.ts"]
  177904c0_fd11_5ea7_1df2_8e57b83ea2db -->|defined in| 7d34d289_ea0e_ec1c_780b_4c297e3a4f60
  style 177904c0_fd11_5ea7_1df2_8e57b83ea2db fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/astro/src/core/errors/printer.ts lines 5–35

export function codeFrame(src: string, loc: ErrorLocation): string {
	if (!loc || loc.line === undefined || loc.column === undefined) {
		return '';
	}
	const lines = normalizeLF(src)
		.split('\n')
		.map((ln) => ln.replace(/\t/g, '  '));
	// grab 2 lines before, and 3 lines after focused line
	const visibleLines = [];
	for (let n = -2; n <= 2; n++) {
		if (lines[loc.line + n]) visibleLines.push(loc.line + n);
	}
	// figure out gutter width
	let gutterWidth = 0;
	for (const lineNo of visibleLines) {
		let w = `> ${lineNo}`;
		if (w.length > gutterWidth) gutterWidth = w.length;
	}
	// print lines
	let output = '';
	for (const lineNo of visibleLines) {
		const isFocusedLine = lineNo === loc.line - 1;
		output += isFocusedLine ? '> ' : '  ';
		output += `${lineNo + 1} | ${lines[lineNo]}\n`;
		if (isFocusedLine)
			output += `${Array.from({ length: gutterWidth }).join(' ')}  | ${Array.from({
				length: loc.column,
			}).join(' ')}^\n`;
	}
	return output;
}