testLineageSaltsSeparateIdenticalCode

tcmts.core.test.hash.testLineageSaltsSeparateIdenticalCode · #ima42yzj · term

A lineage salt gives identical code separate identities.

import { analyzeProject } from "#codebase/tcmts/core/analyze";
import { dir, n } from "#codebase/tcmts/core/test/hash";
import assert from "node:assert/strict";
import fs from "node:fs";
import path from "node:path";

export const testLineageSaltsSeparateIdenticalCode = () => {
  const file = path.join(dir, `salted${n++}.ts`);
  fs.writeFileSync(
    file,
    `export const cacheA = new Map<string, number>();\nexport const cacheB = new Map<string, number>();\n`,
  );
  const run = (saltFor?: (f: string, name: string) => string | undefined) =>
    Object.fromEntries(
      analyzeProject([file], { cacheDir: dir, resolveName: () => "", saltFor }).defs.map((d) => [
        d.nameHint,
        d.hash,
      ]),
    );
  const unsalted = run();
  assert.equal(unsalted.cacheA, unsalted.cacheB, "without salts, identical code is one definition");
  const salted = run((_f, name) => `lib.${name}`);
  assert.notEqual(salted.cacheA, salted.cacheB, "two `new Map()`s are two maps");
  assert.deepEqual(
    run((_f, name) => `lib.${name}`),
    salted,
    "the same salts reproduce the same hashes",
  );
}

testLineageSaltsSeparateIdenticalCode

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