Added image-minimizer (#7772)

Co-authored-by: Mohammed Anas <triallax@tutanota.com>

.github/workflows/image-minimizer.js

@@ -0,0 +1,107 @@
+/*
+ * Script for minimizing big images (jpg,gif,png) when they are uploaded to GitHub and not edited otherwise
+ */
+module.exports = async ({github, context}) => {
+    const IGNORE_KEY = '<!-- IGNORE IMAGE MINIFY -->';
+    const IGNORE_ALT_NAME_END = 'ignoreImageMinify';
+    const IMG_MAX_HEIGHT_PX = 600;
+
+    // Get the body of the image
+    let initialBody = null;
+    if (context.eventName == 'issue_comment') {
+        initialBody = context.payload.comment.body;
+    } else if (context.eventName == 'issues') {
+        initialBody = context.payload.issue.body;
+    } else {
+        console.log('Aborting: No body found');
+        return;
+    }
+    console.log(`Found body: \n${initialBody}\n`);
+
+    // Check if we should ignore the currently processing element
+    if (initialBody.includes(IGNORE_KEY)) {
+        console.log('Ignoring: Body contains IGNORE_KEY');
+        return;
+    }
+
+    // Regex for finding images (simple variant) ![ALT_TEXT](https://*.githubusercontent.com/<number>/<variousHexStringsAnd->.<fileExtension>)
+    const REGEX_IMAGE_LOOKUP = /\!\[(.*)\]\((https:\/\/[-a-z0-9]+\.githubusercontent\.com\/\d+\/[-0-9a-f]{32,512}\.(jpg|gif|png))\)/gm;
+
+    // Check if we found something
+    let foundSimpleImages = REGEX_IMAGE_LOOKUP.test(initialBody);
+    if (!foundSimpleImages) {
+        console.log('Found no simple images to process');
+        return;
+    }
+
+    console.log('Found at least one simple image to process');
+
+    // Require the probe lib for getting the image dimensions
+    const probe = require('probe-image-size');
+
+    // Try to find and replace the images with minimized ones
+    let newBody = await replaceAsync(initialBody, REGEX_IMAGE_LOOKUP, async (match, g1, g2) => {
+        console.log(`Found match '${match}'`);
+        
+        if (g1.endsWith(IGNORE_ALT_NAME_END)) {
+            console.log(`Ignoring match '${match}': IGNORE_ALT_NAME_END`);
+            return match;
+        }
+        
+        let shouldModifiy = false;
+        try {
+            console.log(`Probing ${g2}`);
+            let probeResult = await probe(g2);
+            if (probeResult == null) {
+                throw 'No probeResult';
+            }
+            if (probeResult.hUnits != 'px') {
+                throw `Unexpected probeResult.hUnits (expected px but got ${probeResult.hUnits})`;
+            }
+            
+            shouldModifiy = probeResult.height > IMG_MAX_HEIGHT_PX;
+        } catch(e) {
+            console.log('Probing failed:', e);
+            // Immediately abort
+            return match;
+        }
+        
+        if (shouldModifiy) {
+            console.log(`Modifying match '${match}'`);
+            return `<img alt="${g1}" src="${g2}" height=${IMG_MAX_HEIGHT_PX} />`;
+        }
+        
+        console.log(`Match '${match}' is ok/will not be modified`);
+        return match;
+    });
+
+    // Update the corresponding element
+    if (context.eventName == 'issue_comment') {
+        console.log('Updating comment with id', context.payload.comment.id);
+        await github.rest.issues.updateComment({
+            comment_id: context.payload.comment.id,
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            body: newBody
+        })
+    } else if (context.eventName == 'issues') {
+        console.log('Updating issue', context.payload.issue.number);
+        await github.rest.issues.update({
+            issue_number: context.payload.issue.number,
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            body: newBody
+        });
+    }
+
+    // Asnyc replace function from https://stackoverflow.com/a/48032528
+    async function replaceAsync(str, regex, asyncFn) {
+        const promises = [];
+        str.replace(regex, (match, ...args) => {
+            const promise = asyncFn(match, ...args);
+            promises.push(promise);
+        });
+        const data = await Promise.all(promises);
+        return str.replace(regex, () => data.shift());
+    }
+}

.github/workflows/image-minimizer.yml

@@ -0,0 +1,29 @@
+name: Image Minimizer
+
+on:
+  issue_comment:
+    types: [created, edited]
+  issues:
+    types: [opened, edited]
+
+jobs:
+  try-minimize:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/setup-node@v2
+        with:
+          node-version: 16
+
+      - name: Install probe-image-size
+        run: npm i probe-image-size@7.2.3 --ignore-scripts
+
+      - name: Minimize simple images
+        uses: actions/github-script@v5
+        timeout-minutes: 3
+        with:
+          script: |
+            const script = require('.github/workflows/image-minimizer.js');
+            await script({github, context});