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MediumPro challengePythonJavaScriptTypeScript

Implement Test Runner (describe/it)

TestingFunctions

Implement solve(plan), a tiny describe / it runner. The starter code provides the hooks and test bodies in HOOKS and TESTS; the plan refers to them by name:

{
  suites: [
    {
      name: 'Math',
      beforeEach: 'incrementCounter',   // key of HOOKS, or null
      afterEach: null,                  // key of HOOKS, or null
      tests: [
        { name: 'first', fn: 'counterIsOne' },   // key of TESTS
        { name: 'second', fn: 'counterIsTwo' },
      ],
    },
  ],
}

Rules:

  • Each suite gets a fresh, empty context object ctx, shared by all of its hooks and tests.
  • For each test: run beforeEach(ctx), then the test body fn(ctx), then afterEach(ctx).
  • A test passes only if its body returns exactly true. Otherwise it fails with an error:

- beforeEach threw → its message (the body is skipped, afterEach still runs)
 - the body threw → its message
 - the body returned anything but true → 'Test did not return true'
 - afterEach threw after a passing body → its message

  • Return { passed, failed, results }, where results lists { suite, test, pass, error } in execution order (error is null for a passing test).

Sample tests

Test #1afterEach runs after each test
Input: [{"suites":[{"name":"After","tests":[{"fn":"alwaysTrue","name":"first"},{"fn":"wasCleaned","name":"second"}],"afterEach":"markCleaned","beforeEach":null}]}]
Output: {"failed":0,"passed":2,"results":[{"pass":true,"test":"first","error":null,"suite":"After"},{"pass":true,"test":"second","error":null,"suite":"After"}]}
Test #2beforeEach runs before every test on a shared context
Input: [{"suites":[{"name":"Math","tests":[{"fn":"counterIsOne","name":"first"},{"fn":"counterIsTwo","name":"second"}],"afterEach":null,"beforeEach":"incrementCounter"}]}]
Output: {"failed":0,"passed":2,"results":[{"pass":true,"test":"first","error":null,"suite":"Math"},{"pass":true,"test":"second","error":null,"suite":"Math"}]}
Test #3a body returning false fails
Input: [{"suites":[{"name":"Fail","tests":[{"fn":"onePlusOneIsThree","name":"wrong"}],"afterEach":null,"beforeEach":null}]}]
Output: {"failed":1,"passed":0,"results":[{"pass":false,"test":"wrong","error":"Test did not return true","suite":"Fail"}]}
Test #4a throwing body fails with its message
Input: [{"suites":[{"name":"Throws","tests":[{"fn":"throwsBad","name":"error"}],"afterEach":null,"beforeEach":null}]}]
Output: {"failed":1,"passed":0,"results":[{"pass":false,"test":"error","error":"bad","suite":"Throws"}]}
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