Add option to give warning instead of failing the build if coverage is below threshold

Documentation/MSBuildIntegration.md

@@ -132,6 +132,17 @@ The following command will compare the threshold value with the overall total co
 dotnet test /p:CollectCoverage=true /p:Threshold=80 /p:ThresholdType=line /p:ThresholdStat=total
 ```
 
+You can also specify what action to take when the coverage is below the threshold value using the `/p:ThresholdAct` option. The accepted values are:
+
+* `fail`: which fails the build and is the default option
+* `warning`: which will not stop the build and only gives a warning console message
+
+The following will give a warning, but allows the build to continue when the threshold value is below 80:
+
+```bash
+dotnet test /p:CollectCoverage=true /p:Threshold=80 /p:ThresholdAct=warning
+```
+
 ## Excluding From Coverage
 
 ### Attributes

src/coverlet.console/Program.cs

@@ -36,6 +36,7 @@ static int Main(string[] args)
       var threshold = new Option<string>("--threshold", "Exits with error if the coverage % is below value.") { Arity = ArgumentArity.ZeroOrOne };
       var thresholdTypes = new Option<List<string>>("--threshold-type", () => new List<string>(new string[] { "line", "branch", "method" }), "Coverage type to apply the threshold to.").FromAmong("line", "branch", "method");
       var thresholdStat = new Option<ThresholdStatistic>("--threshold-stat", () => ThresholdStatistic.Minimum, "Coverage statistic used to enforce the threshold value.") { Arity = ArgumentArity.ZeroOrOne };
+      var thresholdAct = new Option<ThresholdAction>("--threshold-act", () => ThresholdAction.Fail, "The action to take when coverage is below the threshold value. Defaults to failing the build.") { Arity = ArgumentArity.ZeroOrOne };
       var excludeFilters = new Option<string[]>("--exclude", "Filter expressions to exclude specific modules and types.") { Arity = ArgumentArity.ZeroOrMore, AllowMultipleArgumentsPerToken = true };
       var includeFilters = new Option<string[]>("--include", "Filter expressions to include only specific modules and types.") { Arity = ArgumentArity.ZeroOrMore, AllowMultipleArgumentsPerToken = true };
       var excludedSourceFiles = new Option<string[]>("--exclude-by-file", "Glob patterns specifying source files to exclude.") { Arity = ArgumentArity.ZeroOrMore, AllowMultipleArgumentsPerToken = true };
@@ -61,6 +62,7 @@ static int Main(string[] args)
         threshold,
         thresholdTypes,
         thresholdStat,
+        thresholdAct,
         excludeFilters,
         includeFilters,
         excludedSourceFiles,
@@ -89,6 +91,7 @@ static int Main(string[] args)
         string thresholdValue = context.ParseResult.GetValueForOption(threshold);
         List<string> thresholdTypesValue = context.ParseResult.GetValueForOption(thresholdTypes);
         ThresholdStatistic thresholdStatValue = context.ParseResult.GetValueForOption(thresholdStat);
+        ThresholdAction thresholdActValue = context.ParseResult.GetValueForOption(thresholdAct);
         string[] excludeFiltersValue = context.ParseResult.GetValueForOption(excludeFilters);
         string[] includeFiltersValue = context.ParseResult.GetValueForOption(includeFilters);
         string[] excludedSourceFilesValue = context.ParseResult.GetValueForOption(excludedSourceFiles);
@@ -115,6 +118,7 @@ static int Main(string[] args)
                       thresholdValue,
                       thresholdTypesValue,
                       thresholdStatValue,
+                      thresholdActValue,
                       excludeFiltersValue,
                       includeFiltersValue,
                       excludedSourceFilesValue,
@@ -142,6 +146,7 @@ private static Task<int> HandleCommand(string moduleOrAppDirectory,
                                                            string threshold,
                                                            List<string> thresholdTypes,
                                                            ThresholdStatistic thresholdStat,
+                                                           ThresholdAction thresholdAct,
                                                            string[] excludeFilters,
                                                            string[] includeFilters,
                                                            string[] excludedSourceFiles,
@@ -380,12 +385,21 @@ string sourceMappingFile
           {
             exceptionMessageBuilder.AppendLine($"The {thresholdStat.ToString().ToLower()} method coverage is below the specified {thresholdTypeFlagValues[ThresholdTypeFlags.Method]}");
           }
-          throw new Exception(exceptionMessageBuilder.ToString());
+
+          switch (thresholdAct)
+          {
+            case ThresholdAction.Warning:
+              logger.LogWarning(exceptionMessageBuilder.ToString());
+              break;
+            case ThresholdAction.Fail:
+              exitCode += (int)CommandExitCodes.CoverageBelowThreshold;
+              throw new Exception(exceptionMessageBuilder.ToString());
+            default:
+              throw new ArgumentOutOfRangeException(nameof(thresholdAct), thresholdAct, "Unhandled threshold action");
+          }
         }
 
         return Task.FromResult(exitCode);
-
-
       }
 
       catch (Win32Exception we) when (we.Source == "System.Diagnostics.Process")

src/coverlet.core/Enums/ThresholdAction.cs

@@ -0,0 +1,11 @@
+// Copyright (c) Toni Solarin-Sodara
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace Coverlet.Core.Enums
+{
+    internal enum ThresholdAction
+    {
+        Fail,
+        Warning
+    }
+}

src/coverlet.msbuild.tasks/CoverageResultTask.cs

@@ -37,6 +37,9 @@ public class CoverageResultTask : BaseTask
     [Required]
     public string ThresholdStat { get; set; }
 
+    [Required]
+    public string ThresholdAct { get; set; }
+
     [Required]
     public ITaskItem InstrumenterState { get; set; }
 
@@ -190,6 +193,16 @@ public override bool Execute()
           thresholdStat = ThresholdStatistic.Total;
         }
 
+        ThresholdAction thresholdAct = ThresholdAction.Fail;
+        if (ThresholdAct.Equals("fail", StringComparison.OrdinalIgnoreCase))
+        {
+          thresholdAct = ThresholdAction.Fail;
+        }
+        else if (ThresholdAct.Equals("warning", StringComparison.OrdinalIgnoreCase))
+        {
+          thresholdAct = ThresholdAction.Warning;
+        }
+
         var coverageTable = new ConsoleTable("Module", "Line", "Branch", "Method");
         var summary = new CoverageSummary();
 
@@ -248,7 +261,16 @@ public override bool Execute()
                 $"The {thresholdStat.ToString().ToLower()} method coverage is below the specified {thresholdTypeFlagValues[ThresholdTypeFlags.Method]}");
           }
 
-          throw new Exception(exceptionMessageBuilder.ToString());
+          switch (thresholdAct)
+          {
+            case ThresholdAction.Warning:
+              _logger.LogWarning(exceptionMessageBuilder.ToString());
+              break;
+            case ThresholdAction.Fail:
+              throw new Exception(exceptionMessageBuilder.ToString());
+            default:
+              throw new ArgumentOutOfRangeException(nameof(thresholdAct), thresholdAct, "Unhandled threshold action");
+          }
         }
       }
       catch (Exception ex)

src/coverlet.msbuild.tasks/coverlet.msbuild.props

@@ -16,6 +16,7 @@
     <Threshold Condition="$(Threshold) == ''">0</Threshold>
     <ThresholdType Condition="$(ThresholdType) == ''">line,branch,method</ThresholdType>
     <ThresholdStat Condition="$(ThresholdStat) == ''">minimum</ThresholdStat>
+    <ThresholdAct Condition="$(ThresholdAct) == ''">fail</ThresholdAct>
     <ExcludeAssembliesWithoutSources Condition="$(ExcludeAssembliesWithoutSources) == ''"></ExcludeAssembliesWithoutSources>
   </PropertyGroup>
   <PropertyGroup>

src/coverlet.msbuild.tasks/coverlet.msbuild.targets

@@ -75,6 +75,7 @@
       Threshold="$(Threshold)"
       ThresholdType="$(ThresholdType)"
       ThresholdStat="$(ThresholdStat)"
+      ThresholdAct="$(ThresholdAct)"
       InstrumenterState="$(InstrumenterState)"
       CoverletMultiTargetFrameworksCurrentTFM="$(_coverletMultiTargetFrameworksCurrentTFM)">
       <Output TaskParameter="ReportItems" ItemName="CoverletReport" />

test/coverlet.msbuild.tasks.tests/CoverageResultTaskTests.cs

@@ -98,6 +98,7 @@ public void Execute_StateUnderTest_WithInstrumentationState_Fake()
         Threshold = "50",
         ThresholdType = "total",
         ThresholdStat = "total",
+        ThresholdAct = "fail",
         InstrumenterState = InstrumenterState
       };
       coverageResultTask.BuildEngine = _buildEngine.Object;