Plugin loading is incorrectly memoized

[thorn0]

Environments:

• Prettier Version: next
• Running Prettier via: API
• Runtime: Node 18
• Operating System: WSL
• Prettier plugins (if any): custom

Steps to reproduce:

import * as prettier from "prettier";

console.log(
  await prettier.format(".", {
    plugins: [
      { parsers: { baz: { parse: () => ({}), astFormat: "baz-ast" } } },
      { printers: { "baz-ast": { print: () => "1" } } },
    ],
    parser: "baz",
  }),
  await prettier.format(".", {
    plugins: [
      { parsers: { baz: { parse: () => ({}), astFormat: "baz-ast" } } },
      { printers: { "baz-ast": { print: () => "2" } } },
    ],
    parser: "baz",
  })
);

The problem is here:

prettier/src/common/load-plugins.js

Line 13 in 2c77149

const memoizedLoad = mem(load, { cacheKey: JSON.stringify });

Both plugins are serialized to the same string by JSON.stringify.

Expected output: 1 2

Actual output: 1 1

[fisker]

Fixed by #14576