From 23dee3d2b8b1190f054681442491f43f923a76bb Mon Sep 17 00:00:00 2001
From: Oliver Booth <me@olivr.me>
Date: Fri, 14 Apr 2023 14:17:33 +0100
Subject: [PATCH] feat: add value-passthru overloads for ConcatIf

---
 X10D.Tests/src/Text/StringTests.cs |  23 ++++-
 X10D/src/Text/StringExtensions.cs  | 136 ++++++++++++++++++++++++++++-
 2 files changed, 154 insertions(+), 5 deletions(-)

diff --git a/X10D.Tests/src/Text/StringTests.cs b/X10D.Tests/src/Text/StringTests.cs
index d462186..6c94343 100644
--- a/X10D.Tests/src/Text/StringTests.cs
+++ b/X10D.Tests/src/Text/StringTests.cs
@@ -112,8 +112,10 @@ public class StringTests
         {
             Assert.That("Hello".ConcatIf(true, " World"), Is.EqualTo("Hello World"));
             Assert.That("Hello".ConcatIf(true, () => " World"), Is.EqualTo("Hello World"));
+            Assert.That("Hello".ConcatIf(true, _ => " World"), Is.EqualTo("Hello World"));
             Assert.That("Hello".ConcatIf(() => true, " World"), Is.EqualTo("Hello World"));
             Assert.That("Hello".ConcatIf(() => true, () => " World"), Is.EqualTo("Hello World"));
+            Assert.That("Hello".ConcatIf(() => true, _ => " World"), Is.EqualTo("Hello World"));
         });
     }
 
@@ -124,23 +126,36 @@ public class StringTests
         {
             Assert.That("Hello".ConcatIf(false, " World"), Is.EqualTo("Hello"));
             Assert.That("Hello".ConcatIf(false, () => " World"), Is.EqualTo("Hello"));
+            Assert.That("Hello".ConcatIf(false, _ => " World"), Is.EqualTo("Hello"));
             Assert.That("Hello".ConcatIf(() => false, " World"), Is.EqualTo("Hello"));
             Assert.That("Hello".ConcatIf(() => false, () => " World"), Is.EqualTo("Hello"));
+            Assert.That("Hello".ConcatIf(() => false, _ => " World"), Is.EqualTo("Hello"));
+            Assert.That("Hello".ConcatIf(_ => false, " World"), Is.EqualTo("Hello"));
+            Assert.That("Hello".ConcatIf(_ => false, () => " World"), Is.EqualTo("Hello"));
+            Assert.That("Hello".ConcatIf(_ => false, _ => " World"), Is.EqualTo("Hello"));
         });
     }
 
     [Test]
     public void ConcatIf_ShouldThrowArgumentNullException_GivenNullConditionFactory()
     {
-        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(null!, "Hello World"));
-        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(null!, () => "Hello World"));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf((Func<bool>)null!, "Hello World"));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf((Func<bool>)null!, () => "Hello World"));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf((Func<bool>)null!, _ => "Hello World"));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf((Func<string?, bool>)null!, "Hello World"));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf((Func<string?, bool>)null!, () => "Hello World"));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf((Func<string?, bool>)null!, _ => "Hello World"));
     }
 
     [Test]
     public void ConcatIf_ShouldThrowArgumentNullException_GivenNullValueFactory()
     {
-        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(true, (Func<string>?)null!));
-        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(() => true, (Func<string>?)null!));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(true, (Func<string?>)null!));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(() => true, (Func<string?>)null!));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(_ => true, (Func<string?>)null!));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(true, (Func<string?, string?>)null!));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(() => true, (Func<string?, string?>)null!));
+        Assert.Throws<ArgumentNullException>(() => _ = "".ConcatIf(_ => true, (Func<string?, string?>)null!));
     }
 
     [Test]
diff --git a/X10D/src/Text/StringExtensions.cs b/X10D/src/Text/StringExtensions.cs
index 4600931..16183f9 100644
--- a/X10D/src/Text/StringExtensions.cs
+++ b/X10D/src/Text/StringExtensions.cs
@@ -157,6 +157,27 @@ public static class StringExtensions
         return conditionFactory() ? value + appendValue : value;
     }
 
+    /// <summary>
+    ///     Appends a string to the current string if the specified condition evaluates to <see langword="true" />.
+    /// </summary>
+    /// <param name="value">The current string.</param>
+    /// <param name="conditionFactory">
+    ///     The function that returns the condition to evaluate, with <paramref name="value" /> given as an argument.
+    /// </param>
+    /// <param name="appendValue">The string to append if the condition is true.</param>
+    /// <returns>The concatenated string.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="conditionFactory" /> is <see langword="null" />.</exception>
+    [Pure]
+    public static string? ConcatIf(this string? value, Func<string?, bool> conditionFactory, string? appendValue)
+    {
+        if (conditionFactory is null)
+        {
+            throw new ArgumentNullException(nameof(conditionFactory));
+        }
+
+        return conditionFactory(value) ? value + appendValue : value;
+    }
+
     /// <summary>
     ///     Appends a string to the current string if the specified condition evaluates to <see langword="true" />.
     /// </summary>
@@ -164,6 +185,7 @@ public static class StringExtensions
     /// <param name="condition">The condition to evaluate.</param>
     /// <param name="valueFactory">The function that returns the string to append if the condition is true.</param>
     /// <returns>The concatenated string.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="valueFactory" /> is <see langword="null" />.</exception>
     [Pure]
     public static string? ConcatIf(this string? value, bool condition, Func<string?> valueFactory)
     {
@@ -175,6 +197,28 @@ public static class StringExtensions
         return condition ? value + valueFactory() : value;
     }
 
+    /// <summary>
+    ///     Appends a string to the current string if the specified condition evaluates to <see langword="true" />.
+    /// </summary>
+    /// <param name="value">The current string.</param>
+    /// <param name="condition">The condition to evaluate.</param>
+    /// <param name="valueFactory">
+    ///     The function that returns the string to append if the condition is true, with <paramref name="value" /> given as an
+    ///     argument.
+    /// </param>
+    /// <returns>The concatenated string.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="valueFactory" /> is <see langword="null" />.</exception>
+    [Pure]
+    public static string? ConcatIf(this string? value, bool condition, Func<string?, string?> valueFactory)
+    {
+        if (valueFactory is null)
+        {
+            throw new ArgumentNullException(nameof(valueFactory));
+        }
+
+        return condition ? value + valueFactory(value) : value;
+    }
+
     /// <summary>
     ///     Appends a string to the current string if the specified condition evaluates to <see langword="true" />.
     /// </summary>
@@ -182,7 +226,9 @@ public static class StringExtensions
     /// <param name="conditionFactory">The function that returns the condition to evaluate.</param>
     /// <param name="valueFactory">The function that returns the string to append if the condition is true.</param>
     /// <returns>The concatenated string.</returns>
-    /// <exception cref="ArgumentNullException"><paramref name="conditionFactory" /> is <see langword="null" />.</exception>
+    /// <exception cref="ArgumentNullException">
+    ///     <paramref name="conditionFactory" /> or <paramref name="valueFactory" /> is <see langword="null" />.
+    /// </exception>
     [Pure]
     public static string? ConcatIf(this string? value, Func<bool> conditionFactory, Func<string?> valueFactory)
     {
@@ -199,6 +245,94 @@ public static class StringExtensions
         return conditionFactory() ? value + valueFactory() : value;
     }
 
+    /// <summary>
+    ///     Appends a string to the current string if the specified condition evaluates to <see langword="true" />.
+    /// </summary>
+    /// <param name="value">The current string.</param>
+    /// <param name="conditionFactory">The function that returns the condition to evaluate.</param>
+    /// <param name="valueFactory">
+    ///     The function that returns the string to append if the condition is true, with <paramref name="value" /> given as an
+    ///     argument.
+    /// </param>
+    /// <returns>The concatenated string.</returns>
+    /// <exception cref="ArgumentNullException">
+    ///     <paramref name="conditionFactory" /> or <paramref name="valueFactory" /> is <see langword="null" />.
+    /// </exception>
+    [Pure]
+    public static string? ConcatIf(this string? value, Func<bool> conditionFactory, Func<string?, string?> valueFactory)
+    {
+        if (conditionFactory is null)
+        {
+            throw new ArgumentNullException(nameof(conditionFactory));
+        }
+
+        if (valueFactory is null)
+        {
+            throw new ArgumentNullException(nameof(valueFactory));
+        }
+
+        return conditionFactory() ? value + valueFactory(value) : value;
+    }
+
+    /// <summary>
+    ///     Appends a string to the current string if the specified condition evaluates to <see langword="true" />.
+    /// </summary>
+    /// <param name="value">The current string.</param>
+    /// <param name="conditionFactory">
+    ///     The function that returns the condition to evaluate, with <paramref name="value" /> given as an argument.
+    /// </param>
+    /// <param name="valueFactory">The function that returns the string to append if the condition is true.</param>
+    /// <returns>The concatenated string.</returns>
+    /// <exception cref="ArgumentNullException">
+    ///     <paramref name="conditionFactory" /> or <paramref name="valueFactory" /> is <see langword="null" />.
+    /// </exception>
+    [Pure]
+    public static string? ConcatIf(this string? value, Func<string?, bool> conditionFactory, Func<string?> valueFactory)
+    {
+        if (conditionFactory is null)
+        {
+            throw new ArgumentNullException(nameof(conditionFactory));
+        }
+
+        if (valueFactory is null)
+        {
+            throw new ArgumentNullException(nameof(valueFactory));
+        }
+
+        return conditionFactory(value) ? value + valueFactory() : value;
+    }
+
+    /// <summary>
+    ///     Appends a string to the current string if the specified condition evaluates to <see langword="true" />.
+    /// </summary>
+    /// <param name="value">The current string.</param>
+    /// <param name="conditionFactory">
+    ///     The function that returns the condition to evaluate, with <paramref name="value" /> given as an argument.
+    /// </param>
+    /// <param name="valueFactory">
+    ///     The function that returns the string to append if the condition is true, with <paramref name="value" /> given as an
+    ///     argument.
+    /// </param>
+    /// <returns>The concatenated string.</returns>
+    /// <exception cref="ArgumentNullException">
+    ///     <paramref name="conditionFactory" /> or <paramref name="valueFactory" /> is <see langword="null" />.
+    /// </exception>
+    [Pure]
+    public static string? ConcatIf(this string? value, Func<string?, bool> conditionFactory, Func<string?, string?> valueFactory)
+    {
+        if (conditionFactory is null)
+        {
+            throw new ArgumentNullException(nameof(conditionFactory));
+        }
+
+        if (valueFactory is null)
+        {
+            throw new ArgumentNullException(nameof(valueFactory));
+        }
+
+        return conditionFactory(value) ? value + valueFactory(value) : value;
+    }
+
     /// <summary>
     ///     Counts the occurrences of a character within the current character span.
     /// </summary>