Add PreferDefaultName property

docs/Reference-for-template.json.md

@@ -492,7 +492,7 @@ See [the article](Binding-and-project-context-evaluation.md#bind-symbols).
 |Name|Description|Default|Mandatory|
 |---|---|---|---|
 |`sourceName`| The text in the source content to replace with the name the user specifies. The value to be replaced with can be given using the `-n` `--name` options while running a template. The template engine will look for any occurrence of the `sourceName` present in the config file and replace it in file names and file contents. If no name is specified by the host, the current directory is used. The value of the `sourceName` is available in built-in `name` symbol and can be used as the source for creating other symbols and condition expressions. Due to implicit forms applied to `sourceName` it is important to select the replacement that doesn't cause the conflicts. See more details about `sourceName` in [the article](Naming-and-default-value-forms.md)||no|
-|`preferDefaultName`| Boolean value that decides which name will be used if no `--name` is specified during creation. If `false` it will use the fallback name (output folder name), if `true` it will use the template's `defaultName`. If no `defaultName` is specified and `preferDefaultName` is set to `true`, the template creation will not succeed. | If not specified, `false` is used. | no
+|`preferDefaultName`| Boolean value that decides which name will be used if no `--name` is specified during creation. If `false` it will use the fallback name (output folder name), if `true` it will use the template's `defaultName`. If no `defaultName` and no fallback name is specified and `preferDefaultName` is set to `true`, the template creation will not succeed with a `MissingMandatoryParam` exception. | If not specified, `false` is used. | no
 |`preferNameDirectory`| Boolean value, indicates whether to create a directory for the template if name is specified but an output directory is not set (instead of creating the content directly in the current directory).|If not specified, `false` is used.|no|
 |`placeholderFilename`|A filename that will be completely ignored, used to indicate that its containing directory should be copied. This allows creation of empty directory in the created template, by having a corresponding source directory containing just the placeholder file. By default, empty directories are ignored.|If not specified, a default value of `"-.-"` is used.|no|
 |`primaryOutputs`|A list of template files for further processing by the host (including post-actions). The path should contain the relative path to the file prior to the symbol based renaming that may happen during template generation. It is defined as an array of [Primary Outputs](#primary-output-definition)||no|

src/Microsoft.TemplateSearch.Common/Abstractions/TemplateSearchData.cs

@@ -48,7 +48,8 @@ public TemplateSearchData(ITemplateInfo templateInfo, IDictionary<string, object
         /// <inheritdoc/>
         public IReadOnlyList<string> ShortNameList => TemplateInfo.ShortNameList;
 
-        public bool PreferDefaultName => TemplateInfo.PreferDefaultName;
+        /// <inheritdoc/>
+        bool ITemplateInfo.PreferDefaultName => TemplateInfo.PreferDefaultName;
 
         /// <inheritdoc/>
         public string? Author => TemplateInfo.Author;

src/Microsoft.TemplateSearch.Common/PublicAPI.Unshipped.txt

@@ -1 +1 @@
-Microsoft.TemplateSearch.Common.TemplateSearchData.PreferDefaultName.get -> bool
+

test/Microsoft.TemplateEngine.Edge.UnitTests/TemplateCacheTests.cs

@@ -210,6 +210,46 @@ public void CanHandleParameters()
             Assert.Equal(2, readTemplate.ParameterDefinitions["param3"].Choices!.Count);
         }
 
+        [Theory]
+        [InlineData(true, "defaultName")]
+        [InlineData(true, null)]
+        [InlineData(false, "anotherDefault")]
+        public void CanHandleDefaultName(bool preferDefaultName, string? defaultName)
+        {
+            IEngineEnvironmentSettings environmentSettings = _environmentSettingsHelper.CreateEnvironment(virtualize: true);
+            SettingsFilePaths paths = new SettingsFilePaths(environmentSettings);
+
+            ITemplate template = A.Fake<ITemplate>();
+            A.CallTo(() => template.Identity).Returns("testIdentity");
+            A.CallTo(() => template.Name).Returns("testName");
+            A.CallTo(() => template.ShortNameList).Returns(new[] { "testShort" });
+            A.CallTo(() => template.PreferDefaultName).Returns(preferDefaultName);
+            A.CallTo(() => template.DefaultName).Returns(defaultName);
+            A.CallTo(() => template.MountPointUri).Returns("testMount");
+            A.CallTo(() => template.ConfigPlace).Returns(".template.config/template.json");
+            IMountPoint mountPoint = A.Fake<IMountPoint>();
+            A.CallTo(() => mountPoint.MountPointUri).Returns("testMount");
+
+            ScanResult result = new ScanResult(mountPoint, new[] { template }, Array.Empty<ILocalizationLocator>(), Array.Empty<(string AssemblyPath, Type InterfaceType, IIdentifiedComponent Instance)>());
+            TemplateCache templateCache = new TemplateCache(new[] { result }, new Dictionary<string, DateTime>(), NullLogger.Instance);
+
+            WriteObject(environmentSettings.Host.FileSystem, paths.TemplateCacheFile, templateCache);
+            var readCache = new TemplateCache(ReadObject(environmentSettings.Host.FileSystem, paths.TemplateCacheFile), NullLogger.Instance);
+
+            Assert.Single(readCache.TemplateInfo);
+            var readTemplate = readCache.TemplateInfo[0];
+            if (preferDefaultName)
+            {
+                Assert.True(readTemplate.PreferDefaultName);
+
+            }
+            else
+            {
+                Assert.False(readTemplate.PreferDefaultName);
+            }
+            Assert.Equal(defaultName, readTemplate.DefaultName);
+        }
+
         private static JObject ReadObject(IPhysicalFileSystem fileSystem, string path)
         {
             using (var fileStream = fileSystem.OpenRead(path))