@ExtendWith(MockitoExtension.class)
class CredentialsInternalTest {

    @Mock
    CIFSContext mockContext;

    /**
     * Simple in-test implementation of CredentialsInternal to exercise the API surface.
     * It validates inputs, records calls, and delegates some behavior to collaborators
     * so we can verify interactions.
     */
    static class TestCredentials implements CredentialsInternal {
        private final String domain;

        assertEquals(0, response.readDataWireFormat(buffer, 0, 100));
    }

    @Test
    @DisplayName("Methods should handle null buffer without validation")
    void testMethodsWithNullBuffer() {
        // The implementation doesn't validate null buffers
        // These methods simply return 0 without accessing the buffer

        // Write methods return 0 without accessing null buffer

/**
 * API action for admin document management.
 * Provides RESTful API endpoints for bulk document operations in the Fess search engine.
 * Supports indexing multiple documents with automatic field validation and default value assignment.
 */
public class ApiAdminDocumentsAction extends FessApiAdminAction {

    // ===================================================================================
    // Constant
    //

// values of maximally occurring errors validated against readQuorum.
func reduceReadQuorumErrs(ctx context.Context, errs []error, ignoredErrs []error, readQuorum int) (maxErr error) {
	return reduceQuorumErrs(ctx, errs, ignoredErrs, readQuorum, errErasureReadQuorum)
}

// reduceWriteQuorumErrs behaves like reduceErrs but only for returning
// values of maximally occurring errors validated against writeQuorum.

import org.codelibs.fess.util.RenderDataUtil;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.ruts.process.ActionRuntime;
import org.lastaflute.web.validation.exception.ValidationErrorException;

/**
 * Admin action for Plugin management.
 * This class provides functionality for installing, deleting, and managing plugins in the Fess system.
 *
 */

    //                                                                        ============
    /**
     * Verifies that the provided CRUD mode matches the expected mode.
     * Throws a validation error if the modes do not match.
     *
     * @param crudMode the actual CRUD mode
     * @param expectedMode the expected CRUD mode
     */

```

## 🏗️ Architecture & Design Patterns

### Core Design Principles
CoreLib follows a **utility-class pattern** where most functionality is exposed through static methods:

- **Assertion-based validation** - All methods validate inputs using `AssertionUtil.assertArgumentNotNull()` and `AssertionUtil.assertArgumentNotEmpty()`

		urlStr     string
		shouldPass bool
	}{
		{"", false},
		{":", false},
		{"http://localhost/", true},
		{"http://127.0.0.1/", true},
		{"proto://myhostname/path", true},
	}

	// Validates fetching local address.
	for i, testCase := range testCases {
		_, err := checkURL(testCase.urlStr)
		if testCase.shouldPass && err != nil {
			t.Errorf("Test %d: expected to pass but got an error: %v\n", i+1, err)
		}

/// tip

To understand environment variables you can read [Environment Variables](../environment-variables.md){.internal-link target=_blank}.

///

## Types and validation { #types-and-validation }

	github.com/VividCortex/ewma v1.2.0 // indirect
	github.com/acarl005/stripansi v0.0.0-20180116102854-5a71ef0e047d // indirect
	github.com/apache/thrift v0.21.0 // indirect
	github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2 // indirect
	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
	github.com/beorn7/perks v1.0.1 // indirect
	github.com/charmbracelet/bubbles v0.20.0 // indirect