@jsdocs-io/extractor/dist/format-signature.js

The API extractor for npm packages powering jsdocs.io

import { format } from "prettier";
export async function formatSignature(kind, signature) {
    const s = signature
        .trim()
        // Remove unnecessary keywords at declaration start.
        .replace(/^export\s+/, "")
        .replace(/^default\s+/, "")
        .replace(/^declare\s+/, "");
    switch (kind) {
        case "variable": {
            // Temporarily replace the invalid variable name `default` before the type.
            const raw = s.replace("default:", "_______:");
            const formatted = await formatWithPrettier(raw);
            return formatted.replace("_______:", "default:");
        }
        case "function": {
            // Temporarily add `let` to format the function like a variable signature.
            const raw = `let ${s.replace("default:", "_______:")}`;
            const formatted = await formatWithPrettier(raw);
            return formatted.replace("_______:", "default:").replace(/^let\s/, "");
        }
        case "class":
        case "interface":
        case "enum":
        case "type":
        case "namespace": {
            // Just format the signature as-is.
            const formatted = await formatWithPrettier(s);
            return formatted;
        }
        case "class-constructor":
        case "class-property":
        case "class-method":
        case "interface-property":
        case "interface-method":
        case "interface-construct-signature":
        case "interface-call-signature":
        case "interface-index-signature":
        case "interface-get-accessor":
        case "interface-set-accessor":
        case "enum-member": {
            // Temporarily wrap members in their parent declaration for formatting.
            const parentKind = kind.split("-")[0];
            const raw = `${parentKind} P { ${s} }`;
            const formattedParent = await formatWithPrettier(raw);
            const formatted = formattedParent
                // Remove parent wrapper on first and last lines.
                .split("\n")
                .slice(1, -1)
                // Remove indentation.
                .map((line) => line.replace(/^\s{2}/, ""))
                .join("\n")
                // Remove trailing comma in enum member signature.
                .replace(/,$/, "");
            return formatted;
        }
    }
}
async function formatWithPrettier(s) {
    try {
        const formatted = (await format(s, { parser: "typescript" })).trim();
        return formatted;
    }
    catch {
        return s;
    }
}