diff --git a/UnityXrefMaps.Tests/UtilsTests.cs b/UnityXrefMaps.Tests/UtilsTests.cs
new file mode 100644
index 0000000..88b78dc
--- /dev/null
+++ b/UnityXrefMaps.Tests/UtilsTests.cs
@@ -0,0 +1,24 @@
+using System.Threading.Tasks;
+
+namespace UnityXrefMaps.Tests;
+
+public class UtilsTests
+{
+    [Fact]
+    public async Task RunCommand_SuccessfulProcess_ReturnsZero()
+    {
+        // `true` always exits with code 0.
+        // RunCommand must surface the exit code so callers can detect failures.
+        int exitCode = await Utils.RunCommand("true", "", _ => { }, _ => { });
+        Assert.Equal(0, exitCode);
+    }
+
+    [Fact]
+    public async Task RunCommand_FailingProcess_ReturnsNonZero()
+    {
+        // `false` always exits with code 1.
+        // Before the fix, RunCommand returned void so exit codes were silently discarded.
+        int exitCode = await Utils.RunCommand("false", "", _ => { }, _ => { });
+        Assert.Equal(1, exitCode);
+    }
+}
diff --git a/UnityXrefMaps.Tests/XrefMapServiceTests.cs b/UnityXrefMaps.Tests/XrefMapServiceTests.cs
new file mode 100644
index 0000000..396371e
--- /dev/null
+++ b/UnityXrefMaps.Tests/XrefMapServiceTests.cs
@@ -0,0 +1,68 @@
+using System.IO;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace UnityXrefMaps.Tests;
+
+public class XrefMapServiceTests
+{
+    private readonly XrefMapService _service = new(NullLogger<XrefMapService>.Instance);
+
+    [Fact]
+    public async Task Load_ZeroColonAtWordBoundary_IsStripped()
+    {
+        // `0: value` in a YAML string value causes the parser to treat it as a nested
+        // mapping, crashing with a type-mismatch. The regex must strip `0:` before parsing.
+        string yaml = """
+            sorted: false
+            references:
+            - uid: SomeType
+              name: SomeType
+              href: SomeType.html
+              commentId: T:SomeType
+              nameWithType: 0: orphan
+            """;
+
+        string filePath = Path.GetTempFileName();
+        try
+        {
+            await File.WriteAllTextAsync(filePath, yaml);
+            XrefMap result = await _service.Load(filePath);
+            Assert.NotNull(result);
+            Assert.Single(result.References!);
+        }
+        finally
+        {
+            File.Delete(filePath);
+        }
+    }
+
+    [Fact]
+    public async Task Load_NonZeroDigitColon_IsPreserved()
+    {
+        // The old regex `(\d):` stripped the colon from every digit-colon sequence, corrupting
+        // legitimate values such as `data1:field` → `data1field` in href or nameWithType fields.
+        // Only `0:` at a word boundary should be stripped.
+        string yaml = """
+            sorted: false
+            references:
+            - uid: SomeType
+              name: SomeType
+              href: SomeType.html
+              commentId: T:SomeType
+              nameWithType: data1:field
+            """;
+
+        string filePath = Path.GetTempFileName();
+        try
+        {
+            await File.WriteAllTextAsync(filePath, yaml);
+            XrefMap result = await _service.Load(filePath);
+            Assert.Equal("data1:field", result.References![0].NameWithType);
+        }
+        finally
+        {
+            File.Delete(filePath);
+        }
+    }
+}
diff --git a/UnityXrefMaps/XrefMapService.cs b/UnityXrefMaps/XrefMapService.cs
index 4b26ee7..c460a18 100644
--- a/UnityXrefMaps/XrefMapService.cs
+++ b/UnityXrefMaps/XrefMapService.cs
@@ -1,76 +1,76 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Text.RegularExpressions;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.Extensions.Logging;
-using YamlDotNet.Serialization;
-
-namespace UnityXrefMaps
-{
-    internal sealed partial class XrefMapService(ILogger<XrefMapService> logger)
-    {
-        private readonly Deserializer _deserializer = new();
-        private readonly Serializer _serializer = new();
-
-        /// <summary>
-        /// Loads a <see cref="XrefMap"/> from a file.
-        /// </summary>
-        /// <param name="filePath">The path of the file.</param>
-        /// <returns>The loaded <see cref="XrefMap"/> from <paramref name="filePath"/>.</returns>
-        public async Task<XrefMap> Load(string filePath, CancellationToken cancellationToken = default)
-        {
-            string xrefMapText = await File.ReadAllTextAsync(filePath, cancellationToken);
-
-            // Remove `0:` strings on the xrefmap that make crash Deserializer
-            xrefMapText = ZeroStringsRegex().Replace(xrefMapText, "$1");
-
-            return _deserializer.Deserialize<XrefMap>(xrefMapText);
-        }
-
-        /// <summary>
-        /// Fix the <see cref="XrefMapReference.Href"/> of <see cref="References"/> of this <see cref="XrefMap"/>.
-        /// </summary>
-        /// <param name="apiUrl">The URL of the online API documentation of Unity.</param>
-        public IEnumerable<XrefMapReference> Process(string apiUrl, IEnumerable<XrefMapReference> references, IEnumerable<string> hrefNamespacesToTrim, bool isPackage)
-        {
-            List<XrefMapReference> fixedReferences = [];
-
-            foreach (XrefMapReference reference in references)
-            {
-                if (!reference.IsValid)
-                {
-                    continue;
-                }
-
-                try
-                {
-                    reference.Href = XRefHrefFixer.Fix(apiUrl, reference, hrefNamespacesToTrim, isPackage);
-
-                    fixedReferences.Add(reference);
-                }
-                catch (Exception e)
-                {
-                    logger.LogWarning(e, "Error fixing href: {Uid}", reference.Uid);
-                }
-            }
-
-            return fixedReferences;
-        }
-
-        /// <summary>
-        /// Saves this <see cref="XrefMap"/> to a file.
-        /// </summary>
-        /// <param name="filePath">The path of the file.</param>
-        public async Task Save(string filePath, XrefMap xrefMap, CancellationToken cancellationToken = default)
-        {
-            string xrefMapText = "### YamlMime:XRefMap\n" + _serializer.Serialize(xrefMap);
-
-            await File.WriteAllTextAsync(filePath, xrefMapText, cancellationToken);
-        }
-
-        [GeneratedRegex(@"(\d):")]
-        private static partial Regex ZeroStringsRegex();
-    }
-}
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text.RegularExpressions;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using YamlDotNet.Serialization;
+
+namespace UnityXrefMaps
+{
+    internal sealed partial class XrefMapService(ILogger<XrefMapService> logger)
+    {
+        private readonly Deserializer _deserializer = new();
+        private readonly Serializer _serializer = new();
+
+        /// <summary>
+        /// Loads a <see cref="XrefMap"/> from a file.
+        /// </summary>
+        /// <param name="filePath">The path of the file.</param>
+        /// <returns>The loaded <see cref="XrefMap"/> from <paramref name="filePath"/>.</returns>
+        public async Task<XrefMap> Load(string filePath, CancellationToken cancellationToken = default)
+        {
+            string xrefMapText = await File.ReadAllTextAsync(filePath, cancellationToken);
+
+            // Remove `0:` strings on the xrefmap that make crash Deserializer
+            xrefMapText = ZeroStringsRegex().Replace(xrefMapText, "0");
+
+            return _deserializer.Deserialize<XrefMap>(xrefMapText);
+        }
+
+        /// <summary>
+        /// Fix the <see cref="XrefMapReference.Href"/> of <see cref="References"/> of this <see cref="XrefMap"/>.
+        /// </summary>
+        /// <param name="apiUrl">The URL of the online API documentation of Unity.</param>
+        public IEnumerable<XrefMapReference> Process(string apiUrl, IEnumerable<XrefMapReference> references, IEnumerable<string> hrefNamespacesToTrim, bool isPackage)
+        {
+            List<XrefMapReference> fixedReferences = [];
+
+            foreach (XrefMapReference reference in references)
+            {
+                if (!reference.IsValid)
+                {
+                    continue;
+                }
+
+                try
+                {
+                    reference.Href = XRefHrefFixer.Fix(apiUrl, reference, hrefNamespacesToTrim, isPackage);
+
+                    fixedReferences.Add(reference);
+                }
+                catch (Exception e)
+                {
+                    logger.LogWarning(e, "Error fixing href: {Uid}", reference.Uid);
+                }
+            }
+
+            return fixedReferences;
+        }
+
+        /// <summary>
+        /// Saves this <see cref="XrefMap"/> to a file.
+        /// </summary>
+        /// <param name="filePath">The path of the file.</param>
+        public async Task Save(string filePath, XrefMap xrefMap, CancellationToken cancellationToken = default)
+        {
+            string xrefMapText = "### YamlMime:XRefMap\n" + _serializer.Serialize(xrefMap);
+
+            await File.WriteAllTextAsync(filePath, xrefMapText, cancellationToken);
+        }
+
+        [GeneratedRegex(@"\b0:")]
+        private static partial Regex ZeroStringsRegex();
+    }
+}