multithreading/src/lib/caller_location.js

The missing standard library for multithreading in JavaScript (Works in the browser, Node.js, Deno, Bun).

// Default internal files to ignore
const internalFiles = [
    "caller_location.ts",
    "caller_location.js",
    "lib.ts",
    "lib.js",
    "internal",
    "node_modules",
    "native",
];
/**
 * Analyzes the stack trace to find the file and coordinates
 * where this function was called.
 */
export function getCallerLocation() {
    const stack = new Error().stack;
    const lines = stack.split("\n");
    let callerLine;
    // Iterate to find the first 'outsider'
    for (let i = 0; i < lines.length; i++) {
        const line = lines[i];
        switch (line.trim()) {
            case "Error":
            case "Error:":
                continue;
        }
        // Check if this line belongs to the library
        const isInternal = internalFiles.some((file) => line.includes(file));
        if (!isInternal) {
            callerLine = line;
            break;
        }
    }
    if (!callerLine) {
        throw new Error("Could not find caller line in stack trace");
    }
    // Handle Bun/Deno/Node stack format differences
    const matchParen = callerLine.match(/\((.*)\)/);
    let pathWithCoords = matchParen
        ? matchParen[1]
        : callerLine.replace(/^\s*at\s+/, "").trim();
    pathWithCoords = pathWithCoords.replace(/^async\s+/, "");
    // Extract coordinates (Format is usually path/to/file.ts:line:col)
    const coordMatch = pathWithCoords.match(/:(\d+):(\d+)$/);
    if (!coordMatch) {
        throw new Error(`Could not parse coordinates from: ${callerLine}`);
    }
    const filePath = pathWithCoords.replace(/:\d+:\d+$/, "");
    // Convert 1-based stack trace coords to 0-based AST coords
    return {
        filePath,
        line: Number(coordMatch[1]) - 1,
        column: Number(coordMatch[2]) - 1,
    };
}