metabuilder/packages/json_script_example/tests

JSON Script Testing Guide

Two testing approaches are supported for JSON scripts:

1. Simple Tests (*.cases.json)

Test functions from script.json with expected outputs.

Structure:

• script.json - Contains the functions to test
• *.cases.json - Contains test cases with inputs and expected outputs

Example:

node test_cli.cjs script.json expressions.cases.json

2. Parameterized Tests (.test.logic.json + .test.parameters.json)

Define test logic once, run with many parameter sets.

Structure:

• *.test.logic.json - Test assertion functions (the test code)
• *.test.parameters.json - Input datasets to test with

Files

math.test.logic.json - Test Logic

Contains test functions that perform assertions:

{
  "functions": [{
    "name": "test_add",
    "params": [{"name": "testCase", "type": "object"}],
    "body": [
      {
        "type": "const_declaration",
        "name": "actual",
        "value": {
          "type": "binary_expression",
          "left": {"type": "member_access", "object": "$ref:params.testCase", "property": "a"},
          "operator": "+",
          "right": {"type": "member_access", "object": "$ref:params.testCase", "property": "b"}
        }
      },
      {
        "type": "return",
        "value": {
          "type": "object_literal",
          "properties": {
            "passed": {
              "type": "binary_expression",
              "left": "$ref:local.actual",
              "operator": "==",
              "right": {"type": "member_access", "object": "$ref:params.testCase", "property": "expected"}
            },
            "actual": "$ref:local.actual"
          }
        }
      }
    ]
  }]
}

math.test.parameters.json - Test Data

Contains test cases organized by function and category:

{
  "test_add": {
    "positive_numbers": [
      {
        "desc": "Adding two positive numbers",
        "input": {"a": 5, "b": 3, "expected": 8}
      },
      {
        "desc": "Adding zero",
        "input": {"a": 10, "b": 0, "expected": 10}
      }
    ],
    "edge_cases": [
      {
        "desc": "Both zero",
        "input": {"a": 0, "b": 0, "expected": 0}
      }
    ]
  }
}

Running Parameterized Tests

node test_parameterized_cli.cjs \
  math.test.logic.json \
  math.test.parameters.json

Output

============================================================
Parameterized Test Results
============================================================

📦 Function: test_add
   8/8 tests passed

  ✅ positive_numbers (3/3)
      ✓ Adding two positive numbers (1ms)
      ✓ Adding zero (0ms)
      ✓ Large numbers (0ms)

  ✅ edge_cases (2/2)
      ✓ Both zero (0ms)
      ✓ Very large numbers (0ms)

============================================================
Overall: 13/13 tests passed (0 failed)
🎉 All parameterized tests passed!

Test Function Return Format

Test logic functions should return:

{
  "passed": true,      // boolean - did the test pass?
  "actual": 8,         // any - actual result
  "expected": 8        // any - expected result (optional)
}

Examples in This Directory

Simple Tests

• expressions.cases.json - Tests for all expression types
• statements.cases.json - Tests for all statement types

Parameterized Tests

• math.test.logic.json + math.test.parameters.json - Math operation tests

Benefits of Parameterized Tests

✅ DRY (Don't Repeat Yourself)

Write test logic once, reuse with many inputs

✅ Easy to Add Cases

Just add entries to test.parameters.json, no code changes needed

✅ Organized by Category

Group related test cases (positive_numbers, edge_cases, etc.)

✅ Clear Separation

• Logic (assertions) in one file
• Data (test cases) in another

✅ Maintainable

Update test logic in one place, affects all test cases

When to Use Each Approach

Use Simple Tests When:

• Testing existing functions from script.json
• Quick smoke tests
• One-off test cases
• Testing the JSON executor itself

Use Parameterized Tests When:

• Many similar test cases with different inputs
• Complex validation logic
• Form validation (valid/invalid cases)
• Edge case testing
• Regression test suites

Creating New Parameterized Tests

1. Create yourtest.test.logic.json with test functions:

   {
     "functions": [{
       "name": "test_myfunction",
       "params": [{"name": "testCase"}],
       "body": [
         {"type": "return", "value": {"passed": true}}
       ]
     }]
   }
   

2. Create yourtest.test.parameters.json with test data:

   {
     "test_myfunction": {
       "category1": [
         {"desc": "Test case 1", "input": {...}}
       ]
     }
   }
   

3. Run the tests:

   node test_parameterized_cli.cjs \
     yourtest.test.logic.json \
     yourtest.test.parameters.json
   

See Also

• JSON Script Runtime README
• JSON Script Specification
• json_script_example Package