Write a quoted empty default as "" instead of dropping it [patch]

CodeBlocker.Test/TemplateTests.cs

@@ -74,6 +74,35 @@ public void ParameterEscapesALoneSurrogateInAQuotedDefaultValue()
 		}
 	}
 
+	[TestMethod]
+	public void ParameterWritesAQuotedEmptyDefaultValue() =>
+		Assert.AreEqual(
+			"string separator = \"\"",
+			Render(new ParameterTemplate { Type = "string", Name = "separator", DefaultValue = "", DefaultValueIsQuoted = true }));
+
+	[TestMethod]
+	public void ParameterWithAnEmptyUnquotedDefaultValueHasNone() =>
+		Assert.AreEqual("string separator", Render(new ParameterTemplate { Type = "string", Name = "separator", DefaultValue = "" }));
+
+	[TestMethod]
+	public void AQuotedEmptyDefaultKeepsAParameterOptional()
+	{
+		MethodTemplate method = new()
+		{
+			Type = "void",
+			Name = "M",
+			Keywords = { "public" },
+			BodyFactory = _ => { },
+			Parameters =
+			{
+				new ParameterTemplate { Type = "int", Name = "count", DefaultValue = "0" },
+				new ParameterTemplate { Type = "string", Name = "separator", DefaultValue = "", DefaultValueIsQuoted = true },
+			},
+		};
+
+		Assert.AreEqual("public void M(int count = 0, string separator = \"\") { }\n", Render(method));
+	}
+
 	[TestMethod]
 	public void ParameterKeepsItsAttributesOnTheDeclarationLine()
 	{
@@ -102,6 +131,12 @@ public void FieldEscapesAQuotedInitialiser() =>
 			"private string p = \"C:\\\\temp\\\\\\\"x\\\"\";\n",
 			Render(new FieldTemplate { Type = "string", Name = "p", Keywords = { "private" }, DefaultValue = "C:\\temp\\\"x\"", DefaultValueIsQuoted = true }));
 
+	[TestMethod]
+	public void FieldWritesAQuotedEmptyInitialiser() =>
+		Assert.AreEqual(
+			"public const string Empty = \"\";\n",
+			Render(new FieldTemplate { Type = "string", Name = "Empty", Keywords = { "public", "const" }, DefaultValue = "", DefaultValueIsQuoted = true }));
+
 	[TestMethod]
 	public void FieldCommentsAndAttributesGoOnTheirOwnLines()
 	{
@@ -190,6 +225,49 @@ public void AShorthandPropertyKeepsItsInitialiser()
 		Assert.AreEqual("public int Count { get; set; } = 7;\n", Render(property));
 	}
 
+	[TestMethod]
+	public void AShorthandPropertyKeepsAQuotedEmptyInitialiser()
+	{
+		PropertyTemplate property = new()
+		{
+			Type = "string",
+			Name = "Prefix",
+			Keywords = { "public" },
+			Getter = AccessorTemplate.Auto(),
+			Setter = AccessorTemplate.Auto(),
+			DefaultValue = "",
+			DefaultValueIsQuoted = true,
+		};
+
+		Assert.AreEqual("public string Prefix { get; set; } = \"\";\n", Render(property));
+	}
+
+	[TestMethod]
+	public void ABracedPropertyKeepsAQuotedEmptyInitialiser()
+	{
+		PropertyTemplate property = new()
+		{
+			Type = "string",
+			Name = "Prefix",
+			Keywords = { "public" },
+			Getter = AccessorTemplate.Auto(),
+			Setter = new AccessorTemplate { Modifier = "private" },
+			DefaultValue = "",
+			DefaultValueIsQuoted = true,
+		};
+
+		Assert.AreEqual(
+			"""
+			public string Prefix
+			{
+				get;
+				private set;
+			} = "";
+
+			""".ReplaceLineEndings("\n"),
+			Render(property));
+	}
+
 	[TestMethod]
 	public void AnAccessorModifierForcesTheBracedForm()
 	{

CodeBlocker/Templates/PropertyTemplate.cs

@@ -125,11 +125,9 @@ private void WriteShorthand(CodeBlocker codeBlocker)
 
 		codeBlocker.Write(" }");
 		WriteDefaultValueTo(codeBlocker);
-		codeBlocker.WriteLine(DefaultValueIsSet ? ";" : string.Empty);
+		codeBlocker.WriteLine(HasDefaultValue ? ";" : string.Empty);
 	}
 
-	private bool DefaultValueIsSet => !string.IsNullOrEmpty(DefaultValue);
-
 	private void WriteAccessorList(CodeBlocker codeBlocker)
 	{
 		codeBlocker.WriteLine();
@@ -145,6 +143,6 @@ private void WriteAccessorList(CodeBlocker codeBlocker)
 		// Scope would not allow.
 		codeBlocker.Write("}");
 		WriteDefaultValueTo(codeBlocker);
-		codeBlocker.WriteLine(DefaultValueIsSet ? ";" : string.Empty);
+		codeBlocker.WriteLine(HasDefaultValue ? ";" : string.Empty);
 	}
 }

CodeBlocker/Templates/TemplateBase.cs

@@ -22,7 +22,8 @@ public abstract class TemplateBase
 	public string Type { get; set; } = string.Empty;
 
 	/// <summary>
-	/// Gets or sets the initialiser or default value. Empty means no initialiser is written.
+	/// Gets or sets the initialiser or default value. Empty means no initialiser is written, unless
+	/// <see cref="DefaultValueIsQuoted"/> is set, in which case it is the empty string <c>""</c>.
 	/// </summary>
 	public string DefaultValue { get; set; } = string.Empty;
 
@@ -33,6 +34,12 @@ public abstract class TemplateBase
 	/// </summary>
 	public bool DefaultValueIsQuoted { get; set; }
 
+	/// <summary>
+	/// Gets a value indicating whether an initialiser is written: <see cref="DefaultValue"/> is not
+	/// empty, or it is quoted, where empty raw text is the empty string literal.
+	/// </summary>
+	private protected bool HasDefaultValue => DefaultValueIsQuoted || !string.IsNullOrEmpty(DefaultValue);
+
 	/// <summary>
 	/// Gets the attributes to write before the declaration, each without its square brackets.
 	/// </summary>
@@ -90,15 +97,15 @@ internal virtual void Validate()
 	}
 
 	/// <summary>
-	/// Writes <c> = value</c> when <see cref="DefaultValue"/> is set, as an escaped string literal
+	/// Writes <c> = value</c> when <see cref="HasDefaultValue"/> is set, as an escaped string literal
 	/// when <see cref="DefaultValueIsQuoted"/> is set.
 	/// </summary>
 	/// <param name="codeBlocker">The <see cref="CodeBlocker"/> to write to.</param>
 	protected void WriteDefaultValueTo(CodeBlocker codeBlocker)
 	{
 		Ensure.NotNull(codeBlocker);
 
-		if (string.IsNullOrEmpty(DefaultValue))
+		if (!HasDefaultValue)
 		{
 			return;
 		}