Use std::string_view instead of absl::string_view in fixture.cc.

Clean up some lint warnings.

Fixes #1306.

PiperOrigin-RevId: 595988916
Change-Id: I0e8584ff8704ea7294cf649664ab447cb1d4ff46

test/CMakeLists.txt

@@ -57,7 +57,6 @@ target_compile_definitions(fixture PUBLIC MJSTATIC)
 target_link_libraries(
   fixture
   PUBLIC absl::core_headers
-         absl::strings
          absl::synchronization
          gtest
          gmock

test/fixture.cc

@@ -14,11 +14,14 @@
 
 #include "test/fixture.h"
 
+#include <cstdio>
 #include <cstring>
 #include <filesystem>
 #include <fstream>
-#include <memory>
+#include <sstream>
+#include <string>
 #include <string_view>
+#include <vector>
 
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
@@ -107,7 +110,7 @@ mjModel* LoadModelFromPath(const char* model_path) {
   return model;
 }
 
-const std::string GetFileContents(const char* path) {
+std::string GetFileContents(const char* path) {
   std::ifstream ifs;
   ifs.open(path, std::ifstream::in);
   EXPECT_FALSE(ifs.fail());
@@ -116,7 +119,7 @@ const std::string GetFileContents(const char* path) {
   return sstream.str();
 }
 
-const std::string SaveAndReadXml(const mjModel* model) {
+std::string SaveAndReadXml(const mjModel* model) {
   EXPECT_THAT(model, testing::NotNull());
 
   constexpr int kMaxPathLen = 1024;

test/fixture.h

@@ -17,13 +17,11 @@
 
 #include <csetjmp>
 #include <cstring>
-#include <optional>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <gtest/gtest.h>
-#include <absl/strings/string_view.h>
-#include <mujoco/mjdata.h>
 #include <mujoco/mjmodel.h>
 #include <mujoco/mujoco.h>
 
@@ -80,14 +78,14 @@ auto MjuErrorMessageFrom(Return (*func)(Args...)) {
 }
 
 // Returns a path to a data file, under the mujoco/test directory.
-const std::string GetTestDataFilePath(absl::string_view path);
+const std::string GetTestDataFilePath(std::string_view path);
 
 // Returns a path to a data file, under the mujoco/model directory.
-const std::string GetModelPath(absl::string_view path);
+const std::string GetModelPath(std::string_view path);
 
 // Returns a newly-allocated mjModel, loaded from the contents of xml.
 // On failure returns nullptr and populates the error array if present.
-mjModel* LoadModelFromString(absl::string_view xml, char* error = nullptr,
+mjModel* LoadModelFromString(std::string_view xml, char* error = nullptr,
                              int error_size = 0, mjVFS* vfs = nullptr);
 
 // Returns a newly-allocated mjModel, loaded from the contents in model_path.
@@ -95,7 +93,7 @@ mjModel* LoadModelFromString(absl::string_view xml, char* error = nullptr,
 mjModel* LoadModelFromPath(const char* model_path);
 
 // Returns a string loaded from first saving the model given an input.
-const std::string SaveAndReadXml(const mjModel* model);
+std::string SaveAndReadXml(const mjModel* model);
 
 // Adds control noise.
 std::vector<mjtNum> GetCtrlNoise(const mjModel* m, int nsteps,