# Test Coverage Summary for Float Precision Fix

## Quick Stats

| Test Suite | Tests | Passed | Failed | Status |
|------------|-------|--------|--------|--------|
| Library Tests | 237 | 237 | 0 | ✅ PASS |
| Tolerance Tests (New) | 25 | 25 | 0 | ✅ PASS |
| **Total** | **262** | **262** | **0** | **✅ PASS** |

## Test File Created

**`tests/test_float_precision_tolerance.rs`** - 25 comprehensive tests covering:

### 1. Bound Propagation (4 tests)
- ✅ try_set_min with small differences
- ✅ try_set_max with small differences  
- ✅ Bounds outside tolerance (should fail)
- ✅ Exact boundary values

### 2. FloatInterval Domain (3 tests)
- ✅ contains with tolerance
- ✅ remove_below near boundary
- ✅ remove_above near boundary

### 3. Small Coefficients (5 tests)
- ✅ I=0.04 (original bug)
- ✅ I=0.001 (even smaller)
- ✅ Very small coefficients (0.001, 0.002)
- ✅ Mixed scale coefficients
- ✅ Negative small coefficients

### 4. Constraint Types (4 tests)
- ✅ float_lin_eq with small coefficients
- ✅ float_lin_le with small coefficients
- ✅ float_lin_le at boundary
- ✅ float_lin_ne constraints

### 5. Precision Config (2 tests)
- ✅ Higher precision (8 decimals)
- ✅ Lower precision (4 decimals)

### 6. Accumulated Errors (2 tests)
- ✅ Multiple operations with rounding
- ✅ Chain of small coefficient operations

### 7. Regression Tests (2 tests)
- ✅ Minimal loan problem
- ✅ Two-step loan calculation

### 8. Edge Cases (3 tests)
- ✅ Zero coefficient
- ✅ Near-zero constant
- ✅ Tolerance at exact boundary

## Code Coverage

### Files Fixed and Tested

1. **src/variables/views.rs** (4 locations)
   - try_set_min for VarF with ValF ✅ Tested
   - try_set_min for VarF with ValI ✅ Tested
   - try_set_max for VarF with ValF ✅ Tested
   - try_set_max for VarF with ValI ✅ Tested

2. **src/variables/domain/float_interval.rs** (3 locations)
   - contains method ✅ Tested
   - remove_below method ✅ Tested
   - remove_above method ✅ Tested

## What the Tests Verify

### ✅ Bug is Fixed
```rust
// BEFORE: NoSolution with I=0.04
// AFTER: X1 = 1.04 ✓

let mut model = Model::default();
let i = model.float(0.0, 10.0);
let x1 = model.float(1.0, 11.0);

model.new(i.eq(0.04));
model.float_lin_eq(&[1.0, -1.0], &[i, x1], -1.0);

let sol = model.solve().unwrap();
let x1_val: f64 = sol.get(x1);
assert!((x1_val - 1.04).abs() < 1e-6); // PASSES ✓
```

### ✅ Tolerance Works Correctly
```rust
// Values within tolerance of boundary should work
model.new(x.ge(0.9999995)); // Within 5e-7 tolerance
assert!(model.solve().is_ok()); // PASSES ✓
```

### ✅ Different Precisions Work
```rust
// 8 decimal places (step = 1e-8, tolerance = 5e-9)
let config = SolverConfig::default().with_float_precision(8);
let mut model = Model::with_config(config);
// Small values work correctly ✓
```

### ✅ No False Positives
```rust
// Bounds clearly outside tolerance correctly fail
model.new(x.ge(0.15)); // Outside domain [0.0, 0.1]
assert!(model.solve().is_err()); // PASSES ✓
```

## Running the Tests

### All tests:
```bash
cargo test
```

### Just tolerance tests:
```bash
cargo test --test test_float_precision_tolerance
```

### Specific test:
```bash
cargo test test_small_float_coefficients_004
```

### With output:
```bash
cargo test --test test_float_precision_tolerance -- --nocapture
```

## Test Results

```
=== Library Tests ===
test result: ok. 237 passed; 0 failed; 1 ignored

=== New Tolerance Tests ===
test result: ok. 25 passed; 0 failed; 0 ignored

=== Example: loan_problem ===
✓ Compiles successfully
✓ Runs without errors
✓ Finds solution with I=0.04
✓ B4 ≈ 65.78 (expected value)
```

## Documentation Created

1. **FLOAT_PRECISION_FIX.md** - Comprehensive fix documentation
2. **FLOAT_PRECISION_TEST_COVERAGE.md** - Detailed test coverage report
3. **tests/test_float_precision_tolerance.rs** - 25 comprehensive tests

## Conclusion

✅ **Complete test coverage** for all 7 fixed code locations  
✅ **25 comprehensive tests** covering all scenarios  
✅ **100% pass rate** - no regressions  
✅ **Original bug confirmed fixed** with regression tests  
✅ **Edge cases validated** - boundaries, precision, accumulated errors  
✅ **Documentation complete** - fix summary and test coverage reports  

The float precision tolerance fix is **fully tested and verified**.
