diff --git a/internal/config/config_test.go b/internal/config/config_test.go
new file mode 100644
index 0000000..fc0f209
--- /dev/null
+++ b/internal/config/config_test.go
@@ -0,0 +1,388 @@
+package config
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"testing"
+)
+
+func TestLegalServiceName(t *testing.T) {
+	tests := []struct {
+		Raw   string
+		Error error
+	}{
+		{
+			`{
+				"/": {
+					"invalid/service-name": {
+
+					}
+				}
+			}`,
+			ErrFormat.Wrap(ErrIllegalServiceName.WrapString("invalid/service-name")),
+		},
+		{
+			`{
+				"/": {
+					"invalid/service/name": {
+
+					}
+				}
+			}`,
+			ErrFormat.Wrap(ErrIllegalServiceName.WrapString("invalid/service/name")),
+		},
+		{
+			`{
+				"/": {
+					"invalid-service-name": {
+
+					}
+				}
+			}`,
+			ErrFormat.Wrap(ErrIllegalServiceName.WrapString("invalid-service-name")),
+		},
+
+		{
+			`{
+				"/": {
+					"valid.service_name": {
+					}
+				}
+			}`,
+			nil,
+		},
+	}
+
+	for i, test := range tests {
+
+		t.Run(fmt.Sprintf("service.%d", i), func(t *testing.T) {
+			_, err := Parse(strings.NewReader(test.Raw))
+
+			if err == nil && test.Error != nil {
+				t.Errorf("expected an error: '%s'", test.Error.Error())
+				t.FailNow()
+			}
+			if err != nil && test.Error == nil {
+				t.Errorf("unexpected error: '%s'", err.Error())
+				t.FailNow()
+			}
+
+			if err != nil && test.Error != nil {
+				if err.Error() != test.Error.Error() {
+					t.Errorf("expected the error '%s' (got '%s')", test.Error.Error(), err.Error())
+					t.FailNow()
+				}
+			}
+		})
+	}
+}
+func TestAvailableMethods(t *testing.T) {
+	reader := strings.NewReader(`{
+		"GET": { "info": "info" },
+		"POST": { "info": "info" },
+		"PUT": { "info": "info" },
+		"DELETE": { "info": "info" }
+	}`)
+	srv, err := Parse(reader)
+	if err != nil {
+		t.Errorf("unexpected error (got '%s')", err)
+		t.FailNow()
+	}
+
+	if srv.Method(http.MethodGet) == nil {
+		t.Errorf("expected method GET to be available")
+		t.Fail()
+	}
+	if srv.Method(http.MethodPost) == nil {
+		t.Errorf("expected method POST to be available")
+		t.Fail()
+	}
+	if srv.Method(http.MethodPut) == nil {
+		t.Errorf("expected method PUT to be available")
+		t.Fail()
+	}
+	if srv.Method(http.MethodDelete) == nil {
+		t.Errorf("expected method DELETE to be available")
+		t.Fail()
+	}
+
+	if srv.Method(http.MethodPatch) != nil {
+		t.Errorf("expected method PATH to be UNavailable")
+		t.Fail()
+	}
+}
+func TestParseEmpty(t *testing.T) {
+	reader := strings.NewReader(`{}`)
+	_, err := Parse(reader)
+	if err != nil {
+		t.Errorf("unexpected error (got '%s')", err)
+		t.FailNow()
+	}
+}
+func TestParseJsonError(t *testing.T) {
+	reader := strings.NewReader(`{
+		"GET": {
+			"info": "info
+		},
+	}`) // trailing ',' is invalid JSON
+	_, err := Parse(reader)
+	if err == nil {
+		t.Errorf("expected error")
+		t.FailNow()
+	}
+}
+
+func TestParseMissingMethodDescription(t *testing.T) {
+	tests := []struct {
+		Raw   string
+		Error error
+	}{
+		{ // missing description
+			`{
+				"GET": {
+
+				}
+			}`,
+			ErrFormat.Wrap(ErrMissingMethodDesc.WrapString("GET /")),
+		},
+		{ // empty description
+			`{
+				"GET": {
+					"info": ""
+				}
+			}`,
+			ErrFormat.Wrap(ErrMissingMethodDesc.WrapString("GET /")),
+		},
+		{ // valid description
+			`{
+				"GET": {
+					"info": "a"
+				}
+			}`,
+			nil,
+		},
+		{ // valid description
+			`{
+				"GET": {
+					"info": "some description"
+				}
+			}`,
+			nil,
+		},
+	}
+
+	for i, test := range tests {
+
+		t.Run(fmt.Sprintf("method.%d", i), func(t *testing.T) {
+			_, err := Parse(strings.NewReader(test.Raw))
+
+			if err == nil && test.Error != nil {
+				t.Errorf("expected an error: '%s'", test.Error.Error())
+				t.FailNow()
+			}
+			if err != nil && test.Error == nil {
+				t.Errorf("unexpected error: '%s'", err.Error())
+				t.FailNow()
+			}
+
+			if err != nil && test.Error != nil {
+				if err.Error() != test.Error.Error() {
+					t.Errorf("expected the error '%s' (got '%s')", test.Error.Error(), err.Error())
+					t.FailNow()
+				}
+			}
+		})
+	}
+
+}
+
+func TestParseParameters(t *testing.T) {
+	tests := []struct {
+		Raw              string
+		Error            error
+		ErrorAlternative error
+	}{
+		{ // invalid param name prefix
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"_param1": {}
+					}
+				}
+			}`,
+			ErrFormat.Wrap(ErrIllegalParamName.WrapString("GET / {_param1}")),
+			nil,
+		},
+		{ // invalid param name suffix
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1_": {}
+					}
+				}
+			}`,
+			ErrFormat.Wrap(ErrIllegalParamName.WrapString("GET / {param1_}")),
+			nil,
+		},
+
+		{ // missing param description
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1": {}
+					}
+				}
+			}`,
+			ErrFormat.Wrap(ErrMissingParamDesc.WrapString("GET / {param1}")),
+			nil,
+		},
+		{ // empty param description
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1": {
+							"info": ""
+						}
+					}
+				}
+			}`,
+			ErrFormat.Wrap(ErrMissingParamDesc.WrapString("GET / {param1}")),
+			nil,
+		},
+
+		{ // missing param type
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1": {
+							"info": "valid"
+						}
+					}
+				}
+			}`,
+			ErrFormat.Wrap(ErrMissingParamType.WrapString("GET / {param1}")),
+			nil,
+		},
+		{ // empty param type
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1": {
+							"info": "valid",
+							"type": ""
+						}
+					}
+				}
+			}`,
+			ErrFormat.Wrap(ErrMissingParamType.WrapString("GET / {param1}")),
+			nil,
+		},
+		{ // valid description + valid type
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1": {
+							"info": "valid",
+							"type": "valid"
+						}
+					}
+				}
+			}`,
+			nil,
+			nil,
+		},
+
+		{ // name conflict with rename
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1": { "info": "valid", "type": "valid" },
+						"param2": { "info": "valid", "type": "valid", "name": "param1" }
+
+					}
+				}
+			}`,
+			// 2 possible errors as map order is not deterministic
+			ErrFormat.Wrap(ErrParamNameConflict.WrapString("GET / {param1}")),
+			ErrFormat.Wrap(ErrParamNameConflict.WrapString("GET / {param2}")),
+		},
+		{ // rename conflict with name
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1": { "info": "valid", "type": "valid", "name": "param2" },
+						"param2": { "info": "valid", "type": "valid" }
+
+					}
+				}
+			}`,
+			// 2 possible errors as map order is not deterministic
+			ErrFormat.Wrap(ErrParamNameConflict.WrapString("GET / {param1}")),
+			ErrFormat.Wrap(ErrParamNameConflict.WrapString("GET / {param2}")),
+		},
+		{ // rename conflict with rename
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1": { "info": "valid", "type": "valid", "name": "conflict" },
+						"param2": { "info": "valid", "type": "valid", "name": "conflict" }
+
+					}
+				}
+			}`,
+			// 2 possible errors as map order is not deterministic
+			ErrFormat.Wrap(ErrParamNameConflict.WrapString("GET / {param1}")),
+			ErrFormat.Wrap(ErrParamNameConflict.WrapString("GET / {param2}")),
+		},
+
+		{ // both renamed with no conflict
+			`{
+				"GET": {
+					"info": "info",
+					"in": {
+						"param1": { "info": "valid", "type": "valid", "name": "freename" },
+						"param2": { "info": "valid", "type": "valid", "name": "freename2" }
+
+					}
+				}
+			}`,
+			nil,
+			nil,
+		},
+	}
+
+	for i, test := range tests {
+
+		t.Run(fmt.Sprintf("method.%d", i), func(t *testing.T) {
+			_, err := Parse(strings.NewReader(test.Raw))
+
+			if err == nil && test.Error != nil {
+				t.Errorf("expected an error: '%s'", test.Error.Error())
+				t.FailNow()
+			}
+			if err != nil && test.Error == nil {
+				t.Errorf("unexpected error: '%s'", err.Error())
+				t.FailNow()
+			}
+
+			if err != nil && test.Error != nil {
+				if err.Error() != test.Error.Error() && err.Error() != test.ErrorAlternative.Error() {
+					t.Errorf("expected the error '%s' (got '%s')", test.Error.Error(), err.Error())
+					t.FailNow()
+				}
+			}
+		})
+	}
+
+}