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fluent-asserts

Assertion Statistics

fluent-asserts provides built-in statistics tracking for monitoring assertion behavior. This is useful for:

  • Monitoring test health in long-running test suites
  • Tracking assertion counts in multi-threaded programs
  • Generating test reports with pass/fail metrics
  • Debugging test behavior

Accessing Statistics

Statistics are available through the Lifecycle singleton:

import fluentasserts.core.lifecycle : Lifecycle;


// Run some assertions
expect(1).to.equal(1);
expect("hello").to.contain("ell");


// Access statistics
auto stats = Lifecycle.instance.statistics;
writeln("Total assertions: ", stats.totalAssertions);
writeln("Passed: ", stats.passedAssertions);
writeln("Failed: ", stats.failedAssertions);

AssertionStatistics Struct

The AssertionStatistics struct contains:

FieldTypeDescription
totalAssertionsintTotal number of assertions executed
passedAssertionsintNumber of assertions that passed
failedAssertionsintNumber of assertions that failed

Resetting Statistics

You can reset all counters to zero:

import fluentasserts.core.lifecycle : Lifecycle;


// Reset all statistics
Lifecycle.instance.resetStatistics();


// Or reset directly on the struct
Lifecycle.instance.statistics.reset();

This is useful when you want to track statistics for a specific phase of testing.

Example: Test Suite Report

import fluentasserts.core.lifecycle : Lifecycle;
import fluent.asserts;


void runTestSuite() {
    // Reset before running suite
    Lifecycle.instance.resetStatistics();


    // Run tests
    runAuthenticationTests();
    runDatabaseTests();
    runApiTests();


    // Generate report
    auto stats = Lifecycle.instance.statistics;
    writefln("Test Suite Complete");
    writefln("  Total: %d", stats.totalAssertions);
    writefln("  Passed: %d (%.1f%%)",
        stats.passedAssertions,
        100.0 * stats.passedAssertions / stats.totalAssertions);
    writefln("  Failed: %d", stats.failedAssertions);
}

Example: Per-Test Statistics

import fluentasserts.core.lifecycle : Lifecycle;
import fluent.asserts;


unittest {
    // Save current statistics
    auto savedStats = Lifecycle.instance.statistics;
    scope(exit) Lifecycle.instance.statistics = savedStats;


    // Reset for this test
    Lifecycle.instance.resetStatistics();


    // Run assertions
    expect(computeValue()).to.equal(42);
    expect(validateInput("test")).to.equal(true);


    // Verify assertion count
    assert(Lifecycle.instance.statistics.totalAssertions == 2);
}

Thread Safety

Statistics are stored in the thread-local Lifecycle instance. Each thread maintains its own statistics. If you need aggregate statistics across threads, you’ll need to collect and combine them manually.

Next Steps