groupImports

tcmts.loader.groupImports · #27gzhmmu · term · runs anywhere

Imports as one statement per module (type-only names in one of their own): import { a, b as c } from "x";, wrapped when long. Default and namespace imports stay as they are. In order of module.

export function groupImports(lines: string[]): string[] {
  const named = new Map<string, { type: boolean; from: string; names: string[] }>();
  const other: { from: string; line: string }[] = [];
  for (const l of lines) {
    const m = /^import (type )?\{ (.+) \} from ("[^"]*");$/.exec(l);
    if (!m) {
      other.push({ from: /from ("[^"]*");$/.exec(l)?.[1] ?? "", line: l });
      continue;
    }
    const key = `${m[1] ?? ""}${m[3]}`;
    const g = named.get(key) ?? { type: !!m[1], from: m[3]!, names: [] };
    named.set(key, g);
    g.names.push(m[2]!);
  }
  const statement = (g: { type: boolean; from: string; names: string[] }) => {
    const head = `import ${g.type ? "type " : ""}`;
    const one = `${head}{ ${g.names.join(", ")} } from ${g.from};`;
    if (one.length <= 120) return one;
    // wrapped: as many names to a line as fit
    const rows: string[] = [];
    for (const n of g.names) {
      const last = rows.at(-1);
      if (last !== undefined && last.length + n.length + 2 <= 116) rows[rows.length - 1] = `${last} ${n},`;
      else rows.push(`${n},`);
    }
    return `${head}{\n${rows.map((r) => `  ${r}`).join("\n")}\n} from ${g.from};`;
  };
  const all = [...[...named.values()].map((g) => ({ from: g.from, type: g.type, line: statement(g) })), ...other.map((o) => ({ ...o, type: false }))];
  return all.sort((a, b) => (a.from < b.from ? -1 : a.from > b.from ? 1 : Number(a.type) - Number(b.type))).map((x) => x.line);
}

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