Adding a tolerance/delta of drop of test coverage. (anuraag016#5)

* Fail Action If percentage diff between old and new goes below delta

* Adding delta parameter

* adding the changes to index.js

* Making the tolerance to 100

Co-authored-by: SANJEEV KUMAR SINGH <sanjeev-mac@SANJEEVs-MacBook-Pro.local>

Author: sanjeev9160

action.yml

@@ -11,6 +11,9 @@ inputs:
   runCommand:
     description: 'custom command to get json-summary'
     default: 'npx jest --coverage --coverageReporters="json-summary" --coverageDirectory="./"'
+  delta:
+    description: 'Difference between the old and final test coverage'
+    default: 100
 branding:
   color: red
   icon: git-pull-request

dist/index.js

@@ -2030,6 +2030,7 @@ function run() {
             const githubToken = core.getInput('accessToken');
             const fullCoverage = JSON.parse(core.getInput('fullCoverageDiff'));
             const commandToRun = core.getInput('runCommand');
+            const delta = Number(core.getInput('delta'));
             const githubClient = github.getOctokit(githubToken);
             const prNumber = github.context.issue.number;
             const branchNameBase = (_a = github.context.payload.pull_request) === null || _a === void 0 ? void 0 : _a.base.ref;
@@ -2046,7 +2047,7 @@ function run() {
                 .trim();
             const diffChecker = new DiffChecker_1.DiffChecker(codeCoverageNew, codeCoverageOld);
             let messageToPost = `Code coverage diff between base branch:${branchNameBase} and head branch: ${branchNameHead} \n`;
-            const coverageDetails = diffChecker.getCoverageDetails(!fullCoverage, `${currentDirectory}/`);
+            const coverageDetails = diffChecker.getCoverageDetails(!fullCoverage, `${currentDirectory}/`, delta);
             if (coverageDetails.length === 0) {
                 messageToPost =
                     'No changes to code coverage between the base branch and the head branch';
@@ -6710,11 +6711,11 @@ class DiffChecker {
             }
         }
     }
-    getCoverageDetails(diffOnly, currentDirectory) {
+    getCoverageDetails(diffOnly, currentDirectory, delta) {
         const keys = Object.keys(this.diffCoverageReport);
         const returnStrings = [];
         for (const key of keys) {
-            if (this.compareCoverageValues(this.diffCoverageReport[key]) !== 0) {
+            if (this.compareCoverageValues(this.diffCoverageReport[key], delta) !== 0) {
                 returnStrings.push(this.createDiffLine(key.replace(currentDirectory, ''), this.diffCoverageReport[key]));
             }
             else {
@@ -6734,10 +6735,15 @@ class DiffChecker {
         }
         return `${name} | ~~${diffFileCoverageData.statements.oldPct}~~ **${diffFileCoverageData.statements.newPct}** | ~~${diffFileCoverageData.branches.oldPct}~~ **${diffFileCoverageData.branches.newPct}** | ~~${diffFileCoverageData.functions.oldPct}~~ **${diffFileCoverageData.functions.newPct}** | ~~${diffFileCoverageData.lines.oldPct}~~ **${diffFileCoverageData.lines.newPct}**`;
     }
-    compareCoverageValues(diffCoverageData) {
+    compareCoverageValues(diffCoverageData, delta) {
         const keys = Object.keys(diffCoverageData);
         for (const key of keys) {
             if (diffCoverageData[key].oldPct !== diffCoverageData[key].newPct) {
+                const oldValue = Number(diffCoverageData[key].oldPct);
+                const newValue = Number(diffCoverageData[key].newPct);
+                if (oldValue - newValue > delta) {
+                    throw Error(`Current PR reduces the test percentage by ${delta}`);
+                }
                 return 1;
             }
         }

src/DiffChecker.ts

@@ -60,11 +60,11 @@ export class DiffChecker {
     }
   }
 
-  getCoverageDetails(diffOnly: boolean, currentDirectory: string): string[] {
+  getCoverageDetails(diffOnly: boolean, currentDirectory: string, delta: number): string[] {
     const keys = Object.keys(this.diffCoverageReport)
     const returnStrings: string[] = []
     for (const key of keys) {
-      if (this.compareCoverageValues(this.diffCoverageReport[key]) !== 0) {
+      if (this.compareCoverageValues(this.diffCoverageReport[key], delta) !== 0) {
         returnStrings.push(
           this.createDiffLine(
             key.replace(currentDirectory, ''),
@@ -99,13 +99,19 @@ export class DiffChecker {
   }
 
   private compareCoverageValues(
-    diffCoverageData: DiffFileCoverageData
+    diffCoverageData: DiffFileCoverageData,
+    delta: number
   ): number {
     const keys: ('lines' | 'statements' | 'branches' | 'functions')[] = <
       ('lines' | 'statements' | 'branches' | 'functions')[]
     >Object.keys(diffCoverageData)
     for (const key of keys) {
       if (diffCoverageData[key].oldPct !== diffCoverageData[key].newPct) {
+        const oldValue: number = Number(diffCoverageData[key].oldPct)
+        const newValue: number = Number(diffCoverageData[key].newPct) 
+        if (oldValue - newValue > delta) {
+          throw Error(`Current PR reduces the test percentage by ${delta}`)
+        }
         return 1
       }
     }

src/main.ts

@@ -12,6 +12,7 @@ async function run(): Promise<void> {
     const githubToken = core.getInput('accessToken')
     const fullCoverage = JSON.parse(core.getInput('fullCoverageDiff'))
     const commandToRun = core.getInput('runCommand')
+    const delta = Number(core.getInput('delta'))
     const githubClient = github.getOctokit(githubToken)
     const prNumber = github.context.issue.number
     const branchNameBase = github.context.payload.pull_request?.base.ref
@@ -37,7 +38,8 @@ async function run(): Promise<void> {
     let messageToPost = `Code coverage diff between base branch:${branchNameBase} and head branch: ${branchNameHead} \n`
     const coverageDetails = diffChecker.getCoverageDetails(
       !fullCoverage,
-      `${currentDirectory}/`
+      `${currentDirectory}/`,
+      delta,
     )
     if (coverageDetails.length === 0) {
       messageToPost =