diff --git a/coremain/run_test.go b/coremain/run_test.go
new file mode 100644
index 000000000..7285aaf3c
--- /dev/null
+++ b/coremain/run_test.go
@@ -0,0 +1,302 @@
+package coremain
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/coredns/caddy"
+)
+
+func TestConfLoader(t *testing.T) {
+	tests := []struct {
+		name          string
+		conf          string
+		contents      []byte
+		serverType    string
+		expectedError bool
+		expectedInput bool
+		checkContents bool
+	}{
+		{
+			name:          "empty conf",
+			conf:          "",
+			serverType:    "dns",
+			expectedError: false,
+			expectedInput: false,
+		},
+		{
+			name:          "non-existent file",
+			conf:          "non-existent-file",
+			serverType:    "dns",
+			expectedError: true,
+			expectedInput: false,
+		},
+		{
+			name:          "stdin input",
+			conf:          "stdin",
+			serverType:    "dns",
+			expectedError: false,
+			expectedInput: false,
+		},
+		{
+			name:          "valid config file",
+			contents:      []byte("example.org:53 {\n    whoami\n}\n"),
+			serverType:    "dns",
+			expectedError: false,
+			expectedInput: true,
+			checkContents: true,
+		},
+		{
+			name:          "empty config file",
+			conf:          "",
+			contents:      []byte(""),
+			serverType:    "dns",
+			expectedError: false,
+			expectedInput: false,
+			checkContents: false,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if len(tc.contents) > 0 {
+				tmpDir := t.TempDir()
+				tmpFile := filepath.Join(tmpDir, "corefile-test")
+				if err := os.WriteFile(tmpFile, tc.contents, 0o644); err != nil {
+					t.Fatalf("Failed to write to temp file: %v", err)
+				}
+				conf = tmpFile
+			} else {
+				conf = tc.conf
+			}
+
+			input, err := confLoader(tc.serverType)
+
+			// Check error
+			if tc.expectedError && err == nil {
+				t.Errorf("Expected error but got none")
+			}
+			if !tc.expectedError && err != nil {
+				t.Errorf("Expected no error but got: %v", err)
+			}
+
+			// Check input
+			if !tc.expectedInput && input != nil {
+				t.Errorf("Expected nil input but got: %v", input)
+			}
+			if tc.expectedInput && input == nil {
+				t.Errorf("Expected non-nil input but got nil")
+			}
+
+			// Check contents if needed
+			if tc.checkContents && input != nil {
+				caddyInput, ok := input.(caddy.CaddyfileInput)
+				if !ok {
+					t.Errorf("Expected input to be caddy.CaddyfileInput")
+				}
+				if string(caddyInput.Contents) != string(tc.contents) {
+					t.Errorf("Expected contents %q, got %q", tc.contents, caddyInput.Contents)
+				}
+				if caddyInput.ServerTypeName != tc.serverType {
+					t.Errorf("Expected ServerTypeName to be %q, got %q", tc.serverType, caddyInput.ServerTypeName)
+				}
+			}
+		})
+	}
+}
+
+func TestDefaultLoader(t *testing.T) {
+	// The working directory matters because defaultLoader() looks for "Corefile" in the current directory
+	tmpDir := t.TempDir()
+	if err := os.Chdir(tmpDir); err != nil {
+		t.Fatalf("Failed to change to temp directory: %v", err)
+	}
+
+	// Test without Corefile
+	input, err := defaultLoader("dns")
+	if err != nil {
+		t.Errorf("Expected no error for missing Corefile, got: %v", err)
+	}
+	if input != nil {
+		t.Errorf("Expected nil input for missing Corefile, got: %v", input)
+	}
+
+	// Test with Corefile
+	testContents := []byte("example.org:53 {\n    whoami\n}\n")
+	if err := os.WriteFile(filepath.Join(tmpDir, "Corefile"), testContents, 0o644); err != nil {
+		t.Fatalf("Failed to write Corefile: %v", err)
+	}
+
+	input, err = defaultLoader("dns")
+	if err != nil {
+		t.Errorf("Expected no error for valid Corefile, got: %v", err)
+	}
+	if input == nil {
+		t.Errorf("Expected non-nil input for valid Corefile")
+	} else {
+		caddyInput, ok := input.(caddy.CaddyfileInput)
+		if !ok {
+			t.Errorf("Expected input to be caddy.CaddyfileInput")
+		}
+		if string(caddyInput.Contents) != string(testContents) {
+			t.Errorf("Expected contents %q, got %q", testContents, caddyInput.Contents)
+		}
+		if caddyInput.ServerTypeName != "dns" {
+			t.Errorf("Expected ServerTypeName to be %q, got %q", "dns", caddyInput.ServerTypeName)
+		}
+	}
+
+	// Create a file but make it unreadable
+	tmpFile := filepath.Join(tmpDir, "Corefile")
+	if err := os.WriteFile(tmpFile, []byte("test"), 0644); err != nil {
+		t.Fatalf("Failed to create test file: %v", err)
+	}
+	if err := os.Chmod(tmpFile, 0000); err != nil {
+		t.Fatalf("Failed to change permissions: %v", err)
+	}
+
+	input, err = defaultLoader("dns")
+	if err == nil {
+		t.Error("Expected error for unreadable Corefile but got none")
+	}
+	if input != nil {
+		t.Error("Expected nil input for unreadable Corefile")
+	}
+}
+
+func TestVersionString(t *testing.T) {
+	caddy.AppName = "TestApp"
+	caddy.AppVersion = "1.0.0"
+
+	expected := "TestApp-1.0.0\n"
+	result := versionString()
+
+	if result != expected {
+		t.Errorf("Expected version string %q, got %q", expected, result)
+	}
+}
+
+func TestReleaseString(t *testing.T) {
+	GitCommit = "a6d2d7b5"
+
+	expected := runtime.GOOS + "/" + runtime.GOARCH + ", " + runtime.Version() + ", " + GitCommit + "\n"
+	result := releaseString()
+
+	if result != expected {
+		t.Errorf("Expected release string %q, got %q", expected, result)
+	}
+}
+
+func TestSetVersion(t *testing.T) {
+	// Test case 1: Development build with nearest tag
+	gitTag = ""
+	gitNearestTag = "v1.2.3"
+	gitShortStat = "1 file changed"
+	GitCommit = "abcdef"
+	buildDate = "2023-05-01"
+
+	setVersion()
+
+	if !devBuild {
+		t.Errorf("Expected devBuild to be true with empty gitTag and non-empty gitShortStat")
+	}
+
+	expectedAppVersion := "1.2.3 (+abcdef 2023-05-01)"
+	if appVersion != expectedAppVersion {
+		t.Errorf("Expected appVersion to be %q, got %q", expectedAppVersion, appVersion)
+	}
+
+	// Test case 2: Release build with tag
+	gitTag = "v2.0.0"
+	gitNearestTag = "v1.9.0"
+	gitShortStat = ""
+
+	setVersion()
+
+	if devBuild {
+		t.Errorf("Expected devBuild to be false with non-empty gitTag and empty gitShortStat")
+	}
+
+	expectedAppVersion = "2.0.0"
+	if appVersion != expectedAppVersion {
+		t.Errorf("Expected appVersion to be %q, got %q", expectedAppVersion, appVersion)
+	}
+
+	// Test case 3: No tags available
+	gitTag = ""
+	gitNearestTag = ""
+	gitShortStat = ""
+	appVersion = "(untracked dev build)" // Reset to default
+
+	setVersion()
+
+	if !devBuild {
+		t.Errorf("Expected devBuild to be true with empty gitTag")
+	}
+
+	expectedAppVersion = "(untracked dev build)"
+	if appVersion != expectedAppVersion {
+		t.Errorf("Expected appVersion to be %q, got %q", expectedAppVersion, appVersion)
+	}
+}
+
+func TestShowVersion(t *testing.T) {
+	// Capture stdout
+	oldStdout := os.Stdout
+	r, w, _ := os.Pipe()
+	os.Stdout = w
+
+	// Set test values
+	caddy.AppName = "TestApp"
+	caddy.AppVersion = "1.0.0"
+	GitCommit = "abc123"
+
+	// Test case 1: Non-dev build
+	devBuild = false
+	gitShortStat = ""
+	gitFilesModified = ""
+
+	showVersion()
+
+	// Restore stdout
+	w.Close()
+	os.Stdout = oldStdout
+
+	var buf bytes.Buffer
+	io.Copy(&buf, r)
+	result := buf.String()
+
+	expected := fmt.Sprintf("TestApp-1.0.0\n%s/%s, %s, abc123\n", runtime.GOOS, runtime.GOARCH, runtime.Version())
+	if result != expected {
+		t.Errorf("Expected version output %q, got %q", expected, result)
+	}
+
+	// Test case 2: Dev build with modified files
+	oldStdout = os.Stdout
+	r, w, _ = os.Pipe()
+	os.Stdout = w
+
+	devBuild = true
+	gitShortStat = "1 file changed, 10 insertions(+), 5 deletions(-)"
+	gitFilesModified = "path/to/modified/file.go"
+
+	showVersion()
+
+	w.Close()
+	os.Stdout = oldStdout
+
+	buf.Reset()
+	io.Copy(&buf, r)
+	result = buf.String()
+
+	expected = fmt.Sprintf("TestApp-1.0.0\n%s/%s, %s, abc123\n1 file changed, 10 insertions(+), 5 deletions(-)\npath/to/modified/file.go\n",
+		runtime.GOOS, runtime.GOARCH, runtime.Version())
+	if result != expected {
+		t.Errorf("Expected version output with dev build info:\n%q\ngot:\n%q", expected, result)
+	}
+}