feat(execution): add on-demand value injection

nuke-build · Jan 17, 2024 · 2bdabd2 · 2bdabd2
1 parent eee9dc0
commit 2bdabd2
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Showing 4 changed files with 45 additions and 14 deletions.
diff --git a/source/Nuke.Build/Execution/Extensions/InjectNonParameterValuesAttribute.cs b/source/Nuke.Build/Execution/Extensions/InjectNonParameterValuesAttribute.cs
@@ -5,7 +5,9 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Linq.Expressions;
 using Nuke.Common.Execution;
+using Nuke.Common.Utilities;
 
 namespace Nuke.Common.ValueInjection;
 
@@ -15,6 +17,23 @@ public void OnBuildInitialized(
         IReadOnlyCollection<ExecutableTarget> executableTargets,
         IReadOnlyCollection<ExecutableTarget> executionPlan)
     {
-        ValueInjectionUtility.InjectValues(Build, x => x.GetType() != typeof(ParameterAttribute));
+        ValueInjectionUtility.InjectValues(Build, (member, attribute) =>
+        {
+            if (attribute.GetType() == typeof(ParameterAttribute))
+                return false;
+
+            if (!Build.GetType().HasCustomAttribute<OnDemandValueInjectionAttribute>() &&
+                !member.HasCustomAttribute<OnDemandAttribute>())
+                return true;
+
+            if (member.HasCustomAttribute<RequiredAttribute>())
+                return false;
+
+            var requiredMembers = executionPlan.SelectMany(x => x.DelegateRequirements)
+                .Where(x => x is not Expression<Func<bool>>)
+                .Select(x => x.GetMemberInfo()).ToList();
+
+            return requiredMembers.Contains(member);
+        });
     }
 }
diff --git a/source/Nuke.Build/Execution/Extensions/InjectParameterValuesAttribute.cs b/source/Nuke.Build/Execution/Extensions/InjectParameterValuesAttribute.cs
@@ -13,6 +13,6 @@ internal class InjectParameterValuesAttribute : BuildExtensionAttributeBase, IOn
 {
     public void OnBuildCreated(IReadOnlyCollection<ExecutableTarget> executableTargets)
     {
-        ValueInjectionUtility.InjectValues(Build, x => x.GetType() == typeof(ParameterAttribute));
+        ValueInjectionUtility.InjectValues(Build, (_, attribute) => attribute.GetType() == typeof(ParameterAttribute));
     }
 }
diff --git a/source/Nuke.Build/Execution/ValueInjectionUtility.cs b/source/Nuke.Build/Execution/ValueInjectionUtility.cs
@@ -45,10 +45,10 @@ object GetValue()
         return (T) (s_valueCache[parameter] = s_valueCache.GetValueOrDefault(parameter) ?? GetValue());
     }
 
-    public static void InjectValues<T>(T instance = default, Func<ValueInjectionAttributeBase, bool> filter = null)
+    public static void InjectValues<T>(T instance = default, Func<MemberInfo, Attribute, bool> filter = null)
     {
-        filter ??= _ => true;
-        InjectValuesInternal(instance, GetInjectionMembers(instance?.GetType() ?? typeof(T)).Where(x => filter(x.Attribute)));
+        filter ??= (_, _) => true;
+        InjectValuesInternal(instance, GetInjectionMembers(instance?.GetType() ?? typeof(T)).Where(x => filter(x.Member, x.Attribute)));
     }
 
     private static void InjectValuesInternal<T>(

diff --git a/source/Nuke.Build/ParameterAttribute.cs b/source/Nuke.Build/ParameterAttribute.cs
@@ -67,20 +67,32 @@ public override object GetValue(MemberInfo member, object instance)
     }
 }
 
+/// <summary>
+/// Marks a member as being required for the whole build.
+/// </summary>
 [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
-public class RequiredAttribute : Attribute
-{
-}
+public class RequiredAttribute : Attribute;
 
+/// <summary>
+/// Suppresses warning logging if value injection throws an exception.
+/// </summary>
 [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
-public class OptionalAttribute : Attribute
-{
-}
+public class OptionalAttribute : Attribute;
 
 [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter)]
-public class SecretAttribute : Attribute
-{
-}
+public class SecretAttribute : Attribute;
+
+/// <summary>
+/// Enables on-demand value injection, where non-parameter members are only injected if required by a target.
+/// </summary>
+[AttributeUsage(AttributeTargets.Class)]
+public class OnDemandValueInjectionAttribute : Attribute;
+
+/// <summary>
+/// Marks a member to be injected only if required by a target.
+/// </summary>
+[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]
+public class OnDemandAttribute : Attribute;
 
 [AttributeUsage(AttributeTargets.Interface, AllowMultiple = false, Inherited = false)]
 public class ParameterPrefixAttribute : Attribute