GeezerVison

Summary

import oracles from '@tanstack/eslint-plugin-oracles' threw in any repo whose TypeScript is 7 or absent. oracle/no-unit-test imported @typescript-eslint/parser at module load, and that parser refuses TypeScript 7 ("typescript-eslint does not support TS 7.0"). Because of this, every config of the plugin failed to load. The field report came from nanostores, which pins TypeScript 7.0.2.

The rule now parses each imported test module with the parser and parser options that ESLint already uses for the file it lints. It parses through ESLint's own Linter, so any configured parser works, espree included, and the module gets ESLint's scope analysis and parent links. @typescript-eslint/parser moves from dependencies to devDependencies.

The new oracle coverage found two more defects, and the repo's own lint found two problems in the first draft:

• espree scopes. Under espree, the rule filtered out every reference, because only typescript-eslint's scope manager sets reference.isValueReference. It then reported a reaching test as undeclared. It now treats a reference as a value unless the scope manager marks it otherwise.
• Silent parse failures. A module that did not parse was skipped silently. Now the rule reports each import, re-export, or star export of a module that does not parse (unparsedModule), with the parser's error. It does this when a file has a test that reaches no part. The rule never throws on it.
• Typed-lint interference (first draft). A nested parse that kept project: true changed the program that the consumer's type-aware rules read for that module. This happened in typescript-eslint's single-run mode (the CLI and CI). The repo's own eslint . reported strictNullChecks errors. The nested parse now drops project, projectService, and programs, because the rule needs only syntax and scope.
• Eager reports (first draft). packages/oracles/vitest.oracle-framework.config.mjs (espree) imports the TS ./vite.config. No test depends on that import, so the unparsedModule report applies only when a test is unreached.

Evidence

• Law:
  1. The plugin and its configs load whether typescript is absent, 5.x, or 7.x (field report round 3).
  2. Rules never throw (maintainer decision 2026-11-08, fix(eslint-plugin-oracles): rules never throw, and oracle rules cannot be disabled inline #6).
  3. An imported module is parsed as ESLint parses the linted file (consumer-parser task).
  4. An unparsed import is reported beside an unreached test.
  5. The nested parse must not change what type-aware rules read.
• Reach: The new lint.part-reach.parsers family gates espree-oracle, espree-oracle-test-uses-part, and oracle-imports-type-syntax-under-espree (fixed seed: 82, 24, and 56 of 103 histories). lint.part-reach.unparseable-companion gates oracle-imports-unparseable-companion (20). The new lint.part-reach.parser-switch law (one ESLint instance lints the TS oracle file, then the JS one, against the same modules) gates oracle-imports-type-syntax-under-espree (22). The TS environment is a one-shot environment fact. A focused test, tests/consumer-typescript.test.js, covers it with 3 child-process cases.
• RED: On the d1b508a rule, 13 of 84 tests fail:
  • Absent TS: Cannot find module 'typescript'.
  • TS 7 stub: typescript-eslint does not support TS 7.0.
  • espree: - "unit:t0" + "undeclared:t0".
  • Broken import: - "unparsed:broken.ts" + [].
• GREEN: The plugin suite passes (17 files, 4310 tests, 2 workers). typecheck, root and package eslint (0 errors), prettier --check, sherif, and publint --strict all pass. In a copy of the nanostores repro, the plugin loads, and it lints an espree-readable oracle file.
• Mutant: Each mutant fails a named check:
  • (a) top-level parser import restored: consumer-typescript.
  • (b) fixed espree, or fixed typescript-eslint: parsers, parser-switch, and others.
  • (c) a parse error that throws: recorded as threw: by the charge helper.
  • (d) the isValueReference check restored: parsers.
  • (e) a parse cache that ignores the parser: parser-switch.
  • (f) type-aware options kept: typed-lint-isolation.
  • (g) eager reports: parsers and unparseable-companion.
• Limits:
  • The nested parse uses the linted file's language options, not the imported module's own. A JS oracle that imports a TS module with type syntax cannot follow reach through it, and gets the report when a test is unreached.
  • Only direct declarations are reported. A transitive unparseable module is not.
  • Only two parsers are exercised.
  • The TS 7 check uses a stub of TS 7's shape. The real 7.0.2 package was exercised only in the nanostores copy.
  • ESLint 10 was not run.
  • Under TS 7, typescript-eslint itself cannot load, so a TS 7 repo still cannot lint .ts oracle files with ESLint.

Review round

A code review found no high-severity defect. This PR fixes these findings:

• Only the read and the parse of an imported module are caught now. An error in the rule's own analysis of a parsed module is a rule bug. The rule no longer reports it as a parse failure.
• The nested Linter ignores the imported module's eslint comments (noInlineConfig). So they run no core rules and print no environment warnings.
• The changeset states two behaviors that adopters will see. The rule parses a module with the linted file's parser. Only direct imports report a parse failure.

One finding is older than this PR and is not fixed here: isProductionModule parses a package.json without a guard, so a malformed manifest makes the rule throw. It goes to the follow-up that makes every rule report malformed settings and files instead of throwing. The parse cache compares language options by identity, so a lint that alternates .ts and .tsx files parses shared helpers again. That costs time only, and the cache holds one entry for each file.

Code weight

no-unit-test.js grows by 269 bytes min+gzip (5833 to 6102). The plugin no longer installs @typescript-eslint/parser and its tree (about 2.5 MB), or that tree's typescript peer. Removing setParents paid for part of the growth, because ESLint's Linter sets parents. The rest is the fatal-message check, the type-aware option strip, the report, and the cache key.

For the maintainer

• Check law 4: the unparsedModule report applies only when a test in the file reaches no part. The brief asked for a report on every parse failure. That broke the repo's own lint on a legal JS config that imports a TS config.
• Check the type-aware option strip (law 5). It departs from "use its parserOptions" for those three keys.
• Consider docs for TS 7 adopters. With this fix the plugin loads, but typescript-eslint does not support TS 7.0, so .ts oracle files need the TS 6 side-by-side setup that typescript-eslint documents.

This pull request and its description were written by Isaac.