Customize PR instructions based on files modified (#6685)

* Customize PR message based on files modified

* Update GitHub REST API method in create-instruction.js

* Handle unresolved promises on GHA workflow and script files

* Always include a header instructions and add heavy line breaks between sections

* Fix: convert tabs to spaces

.github/workflows/pr-instructions.yml

@@ -19,8 +19,9 @@ jobs:
         with:
           script: |
             const script = require('./github-actions/pr-instructions/create-instruction.js')
-            const instruction = script({g: github, c: context})
-            return JSON.stringify({ instruction: instruction, issueNum: context.payload.number })
+            return script({g: github, c: context}).then((instruction) => {
+              return JSON.stringify({ instruction: instruction, issueNum: context.payload.number })
+            })
       
       # Create an artifact with the message
       - name: Create Artifacts

github-actions/pr-instructions/create-instruction.js

@@ -9,10 +9,16 @@ const fs = require('fs');
  * @param {Object} c - context object
  * @returns {string} string containing commandline instructions, URI encoded since the backtick character causes a problem in *  the artifact
  */
-function main({ g, c }) {
+async function main({ g, c }) {
     github = g;
     context = c;
-    return encodeURI(compositeInstruction());   
+    return encodeURI(await compositeInstruction());   
+}
+
+function formatHeaderInstruction() {
+    const path = './github-actions/pr-instructions/pr-instructions-header.md'
+    const headerInstruction = fs.readFileSync(path).toString('utf-8')
+    return headerInstruction
 }
 
 function formatPullComment(instruction) {
@@ -23,7 +29,7 @@ function formatPullComment(instruction) {
 }
 
 function formatContribComment(instruction){
-	const path = './github-actions/pr-instructions/pr-instructions-contrib-template.md'
+    const path = './github-actions/pr-instructions/pr-instructions-contrib-template.md'
     const text = fs.readFileSync(path).toString('utf-8');
     const completedInstructions = text.replace('${previewContribInstructions}', instruction);
     return completedInstructions;
@@ -41,16 +47,48 @@ git pull ${cloneURL} ${nameOfFromBranch}`
 }
 
 function createContribInstruction(){
-	const nameOfCollaborator = context.payload.pull_request.head.repo.owner.login;
+    const nameOfCollaborator = context.payload.pull_request.head.repo.owner.login;
     const nameOfFromBranch = context.payload.pull_request.head.ref;
-	const previewContribURL = `https://github.com/${nameOfCollaborator}/website/blob/${nameOfFromBranch}/CONTRIBUTING.md`
-	return previewContribURL;
+    const previewContribURL = `https://github.com/${nameOfCollaborator}/website/blob/${nameOfFromBranch}/CONTRIBUTING.md`
+    return previewContribURL;
+}
+
+async function getModifiedFiles() {
+    const prNumber = context.payload.pull_request.number;
+    const repoName = context.payload.pull_request.head.repo.name;
+    const ownerName = context.payload.pull_request.head.repo.owner.login;
+
+    // Gets the list of files modified in the pull request and destructures the data object into a files variable
+    const { data: files } = await github.rest.pulls.listFiles({
+        owner: ownerName,
+        repo: repoName,
+        pull_number: prNumber
+    });
+    // Maps the files array to only include the filename of each file
+    const modifiedFiles = files.map(file => file.filename);
+
+    return modifiedFiles;
 }
 
-function compositeInstruction() {
-	const completedPullInstruction = formatPullComment(createPullInstruction());
-	const completedContribInstruction = formatContribComment(createContribInstruction());
-	return completedPullInstruction + completedContribInstruction;
+async function compositeInstruction() {
+    const modifiedFiles = await getModifiedFiles();
+    const isContributingModified = modifiedFiles.includes('CONTRIBUTING.md');
+    const isOnlyContributingModified = isContributingModified && modifiedFiles.length === 1;
+
+    const pullRequestHeader = formatHeaderInstruction();
+    let completedPullInstruction = '';
+    let completedContribInstruction = '';
+
+    // Only includes the pull request instructions if multiple files, including CONTRIBUTING.md, are modified
+    if (!isOnlyContributingModified) {
+        completedPullInstruction = formatPullComment(createPullInstruction());
+    }
+    // Only include the contributing instructions if the CONTRIBUTING.md file is modified
+    if (isContributingModified) {
+        completedContribInstruction = formatContribComment(createContribInstruction());
+    }
+
+    return pullRequestHeader + completedPullInstruction + completedContribInstruction;
 }
 
 module.exports = main

github-actions/pr-instructions/pr-instructions-contrib-template.md

@@ -1,6 +1,6 @@
 <!-- Note: Commandline instructions are added into where the placeholder string first appears --->
 
-------------------
+---
 
 Note that CONTRIBUTING.md cannot previewed locally; rather it should be previewed at this URL:
 

github-actions/pr-instructions/pr-instructions-header.md

@@ -0,0 +1,3 @@
+<!-- This header instruction is added into every Pull Request -->
+
+Want to review this pull request? Take a look at [this documentation](https://github.com/hackforla/website/wiki/How-to-Review-Pull-Requests) for a step by step guide!

github-actions/pr-instructions/pr-instructions-template.md

@@ -1,9 +1,9 @@
 <!-- Note: Commandline instructions are added into where the placeholder string first appears --->
 
-Want to review this pull request? Take a look at [this documentation](https://github.com/hackforla/website/wiki/How-to-Review-Pull-Requests) for a step by step guide!
+---
 
 From your project repository, check out a new branch and test the changes.
 
 ```
 ${commandlineInstructions}
-```
+```