Add unit test of valid and unique Exporter IDs, rename assjson id

"json" is a very vague exporter ID, change to "assjson"

Add a unit test to ensure all exporter have unique IDs
and that they all have an ID, description and extension

code/Assjson/json_exporter.cpp

@@ -34,15 +34,6 @@ namespace Assimp {
 
 void ExportAssimp2Json(const char*, Assimp::IOSystem*, const aiScene*, const Assimp::ExportProperties*);
 
-Exporter::ExportFormatEntry Assimp2Json_desc = Assimp::Exporter::ExportFormatEntry(
-    "json",
-    "Plain JSON representation of the Assimp scene data structure",
-    "json",
-    &ExportAssimp2Json,
-    0u
-);
-
-
 // small utility class to simplify serializing the aiScene to Json
 class JSONWriter {
 public:

code/Common/Exporter.cpp

@@ -167,7 +167,7 @@ Exporter::ExportFormatEntry gExporters[] =
 #endif
 
 #ifndef ASSIMP_BUILD_NO_ASSXML_EXPORTER
-    Exporter::ExportFormatEntry( "assxml", "Assxml Document", "assxml" , &ExportSceneAssxml, 0 ),
+    Exporter::ExportFormatEntry( "assxml", "Assimp XML Document", "assxml" , &ExportSceneAssxml, 0 ),
 #endif
 
 #ifndef ASSIMP_BUILD_NO_X3D_EXPORTER
@@ -183,8 +183,8 @@ Exporter::ExportFormatEntry gExporters[] =
     Exporter::ExportFormatEntry( "3mf", "The 3MF-File-Format", "3mf", &ExportScene3MF, 0 ),
 #endif
 
-#ifndef ASSIMP_BUILD_NO_Assjson_EXPORTER
+#ifndef ASSIMP_BUILD_NO_ASSJSON_EXPORTER
-    Exporter::ExportFormatEntry("json", "Plain JSON representation of the Assimp scene data structure", "json", &ExportAssimp2Json, 0)
+    Exporter::ExportFormatEntry( "assjson", "Assimp JSON Document", "json", &ExportAssimp2Json, 0)
 #endif
 };
 

test/unit/ImportExport/utAssjsonImportExport.cpp

@@ -57,7 +57,7 @@ public:
         const aiScene *scene = importer.ReadFile(ASSIMP_TEST_MODELS_DIR "/OBJ/spider.obj", aiProcess_ValidateDataStructure);
 
         Exporter exporter;
-        aiReturn res = exporter.Export(scene, "json", "./spider_test.json");
+        aiReturn res = exporter.Export(scene, "assjson", "./spider_test.json");
         return aiReturn_SUCCESS == res;
     }
 };

test/unit/ImportExport/utExporter.cpp

@@ -71,3 +71,32 @@ TEST_F(ExporterTest, ProgressHandlerTest) {
     TestProgressHandler *ph(new TestProgressHandler);
     exporter.SetProgressHandler(ph);
 }
+
+// Make sure all the registered exporters have useful descriptions
+TEST_F(ExporterTest, ExporterIdTest) {
+    Exporter exporter;
+    size_t exportFormatCount = exporter.GetExportFormatCount();
+    EXPECT_NE(0, exportFormatCount) << "No registered exporters";
+    typedef std::map<std::string, const aiExportFormatDesc*> ExportIdMap;
+    ExportIdMap exporterMap;
+    for (size_t i = 0; i < exportFormatCount; ++i)
+    {
+        // Check that the exporter description exists and makes sense
+        const aiExportFormatDesc* desc = exporter.GetExportFormatDescription(i);
+        ASSERT_NE(nullptr, desc) << "Missing aiExportFormatDesc at index " << i;
+        EXPECT_NE(nullptr, desc->id) << "Null exporter ID at index " << i;
+        EXPECT_STRNE("", desc->id) << "Empty exporter ID at index " << i;
+        EXPECT_NE(nullptr, desc->description) << "Null exporter description at index " << i;
+        EXPECT_STRNE("", desc->description) << "Empty exporter description at index " << i;
+        EXPECT_NE(nullptr, desc->fileExtension) << "Null exporter file extension at index " << i;
+        EXPECT_STRNE("", desc->fileExtension) << "Empty exporter file extension at index " << i;
+
+        // Check the ID is unique
+        std::string key(desc->id);
+        std::pair<ExportIdMap::iterator, bool> result = exporterMap.emplace(key, desc);
+        EXPECT_TRUE(result.second) << "Duplicate exported id: '" << key << "' " << desc->description << " *." << desc->fileExtension << " at index " << i;
+    }
+
+    const aiExportFormatDesc* desc = exporter.GetExportFormatDescription(exportFormatCount);
+    EXPECT_EQ(nullptr, desc) << "More exporters than claimed";
+}