presets: Fix buildPreset "targets" not allowing a single string

Fixes: #22272

Source/cmCMakePresetsFile.cxx

@@ -184,8 +184,8 @@ auto const PresetVectorStringHelper =
     ReadFileResult::READ_OK, ReadFileResult::INVALID_PRESET,
     PresetStringHelper);
 
-ReadFileResult PresetInheritsHelper(std::vector<std::string>& out,
-                                    const Json::Value* value)
+ReadFileResult PresetVectorOneOrMoreStringHelper(std::vector<std::string>& out,
+                                                 const Json::Value* value)
 {
   out.clear();
   if (!value) {
@@ -312,8 +312,8 @@ auto const ConfigurePresetHelper =
   cmJSONObjectHelper<ConfigurePreset, ReadFileResult>(
     ReadFileResult::READ_OK, ReadFileResult::INVALID_PRESET, false)
     .Bind("name"_s, &ConfigurePreset::Name, PresetStringHelper)
-    .Bind("inherits"_s, &ConfigurePreset::Inherits, PresetInheritsHelper,
-          false)
+    .Bind("inherits"_s, &ConfigurePreset::Inherits,
+          PresetVectorOneOrMoreStringHelper, false)
     .Bind("hidden"_s, &ConfigurePreset::Hidden, PresetBoolHelper, false)
     .Bind<std::nullptr_t>("vendor"_s, nullptr,
                           VendorHelper(ReadFileResult::INVALID_PRESET), false)
@@ -340,7 +340,8 @@ auto const BuildPresetHelper =
   cmJSONObjectHelper<BuildPreset, ReadFileResult>(
     ReadFileResult::READ_OK, ReadFileResult::INVALID_PRESET, false)
     .Bind("name"_s, &BuildPreset::Name, PresetStringHelper)
-    .Bind("inherits"_s, &BuildPreset::Inherits, PresetInheritsHelper, false)
+    .Bind("inherits"_s, &BuildPreset::Inherits,
+          PresetVectorOneOrMoreStringHelper, false)
     .Bind("hidden"_s, &BuildPreset::Hidden, PresetBoolHelper, false)
     .Bind<std::nullptr_t>("vendor"_s, nullptr,
                           VendorHelper(ReadFileResult::INVALID_PRESET), false)
@@ -356,7 +357,8 @@ auto const BuildPresetHelper =
           &BuildPreset::InheritConfigureEnvironment, PresetOptionalBoolHelper,
           false)
     .Bind("jobs"_s, &BuildPreset::Jobs, PresetOptionalIntHelper, false)
-    .Bind("targets"_s, &BuildPreset::Targets, PresetVectorStringHelper, false)
+    .Bind("targets"_s, &BuildPreset::Targets,
+          PresetVectorOneOrMoreStringHelper, false)
     .Bind("configuration"_s, &BuildPreset::Configuration, PresetStringHelper,
           false)
     .Bind("cleanFirst"_s, &BuildPreset::CleanFirst, PresetOptionalBoolHelper,
@@ -657,7 +659,8 @@ auto const TestPresetHelper =
   cmJSONObjectHelper<TestPreset, ReadFileResult>(
     ReadFileResult::READ_OK, ReadFileResult::INVALID_PRESET, false)
     .Bind("name"_s, &TestPreset::Name, PresetStringHelper)
-    .Bind("inherits"_s, &TestPreset::Inherits, PresetInheritsHelper, false)
+    .Bind("inherits"_s, &TestPreset::Inherits,
+          PresetVectorOneOrMoreStringHelper, false)
     .Bind("hidden"_s, &TestPreset::Hidden, PresetBoolHelper, false)
     .Bind<std::nullptr_t>("vendor"_s, nullptr,
                           VendorHelper(ReadFileResult::INVALID_PRESET), false)

Tests/RunCMake/CMakePresetsBuild/Good.json.in

@@ -73,6 +73,11 @@
             "vendor": {
                 "example.com": "value"
             }
+        },
+        {
+            "name": "singleTarget",
+            "inherits": "build-default",
+            "targets": "good"
         }
     ]
 }

Tests/RunCMake/CMakePresetsBuild/RunCMakeTest.cmake

@@ -70,7 +70,7 @@ else()
   set(Good_json_jobs [["jobs": 0,]])
 endif()
 
-run_cmake_build_presets(Good "default;other" "build-other;withEnvironment;noEnvironment;macros;vendorObject")
+run_cmake_build_presets(Good "default;other" "build-other;withEnvironment;noEnvironment;macros;vendorObject;singleTarget")
 run_cmake_build_presets(InvalidConfigurePreset "default" "badConfigurePreset")
 
 set(CMakePresetsBuild_BUILD_ONLY 1)