Fixes #39 Implements Negative Difference Threshold (#54)

Author: tm1000

__tests__/utils.test.ts

@@ -130,6 +130,7 @@ test('getInputs', () => {
     artifactDownloadWorkflowNames: null,
     artifactName: 'coverage-%name%',
     negativeDifferenceBy: 'package',
+    negativeDifferenceThreshold: -0,
     retention: undefined,
     //This is a cheat
     withBaseCoverageTemplate: f.withBaseCoverageTemplate,

src/interfaces.ts

@@ -26,6 +26,7 @@ export interface Inputs {
   retention: number | undefined
   withBaseCoverageTemplate: string
   withoutBaseCoverageTemplate: string
+  negativeDifferenceThreshold: number
 }
 
 export interface Files {

src/main.ts

@@ -117,7 +117,8 @@ async function generateMarkdown(
     markdownFilename,
     negativeDifferenceBy,
     withBaseCoverageTemplate,
-    withoutBaseCoverageTemplate
+    withoutBaseCoverageTemplate,
+    negativeDifferenceThreshold
   } = getInputs()
   const overallDifferencePercentage = baseCoverage
     ? roundPercentage(headCoverage.coverage - baseCoverage.coverage)
@@ -126,16 +127,18 @@ async function generateMarkdown(
   core.debug(`headCoverage: ${headCoverage.coverage}`)
   core.debug(`baseCoverage: ${baseCoverage?.coverage}`)
   core.debug(`overallDifferencePercentage: ${overallDifferencePercentage}`)
+  core.debug(`negativeDifferenceThreshold: ${negativeDifferenceThreshold}`)
 
   if (
     failOnNegativeDifference &&
     negativeDifferenceBy === 'overall' &&
     overallDifferencePercentage !== null &&
     overallDifferencePercentage < 0 &&
+    overallDifferencePercentage < negativeDifferenceThreshold &&
     baseCoverage
   ) {
     core.setFailed(
-      `FAIL: Overall coverage of dropped ${overallDifferencePercentage}%, from ${baseCoverage.coverage}% to ${headCoverage.coverage}%.`
+      `FAIL: Overall coverage of dropped ${overallDifferencePercentage}%, from ${baseCoverage.coverage}% to ${headCoverage.coverage}% which is below minimum threshold of ${-negativeDifferenceThreshold}%`
     )
   }
 
@@ -200,10 +203,11 @@ async function generateMarkdown(
           failOnNegativeDifference &&
           negativeDifferenceBy === 'package' &&
           differencePercentage !== null &&
-          differencePercentage < 0
+          differencePercentage < 0 &&
+          differencePercentage < negativeDifferenceThreshold
         ) {
           core.setFailed(
-            `${headCoverage.files[hash].relative} coverage difference was ${differencePercentage}%`
+            `${headCoverage.files[hash].relative} coverage difference was ${differencePercentage}% which is below threshold of ${-negativeDifferenceThreshold}%`
           )
         }
 

src/utils.ts

@@ -343,6 +343,9 @@ export function getInputs(): Inputs {
     core.getInput('file_coverage_warning_max') || '75'
   )
 
+  const negativeDifferenceThreshold =
+    parseFloat(core.getInput('negative_difference_threshold') || '0') * -100
+
   const failOnNegativeDifference =
     core.getInput('fail_on_negative_difference') === 'true' ? true : false
 
@@ -389,7 +392,8 @@ export function getInputs(): Inputs {
     negativeDifferenceBy,
     retention: retentionDays,
     withoutBaseCoverageTemplate,
-    withBaseCoverageTemplate
+    withBaseCoverageTemplate,
+    negativeDifferenceThreshold
   }
 
   return inputs