Handle image name on disk if already exists

src/uploads/images/imageResizer.js

@@ -1,16 +1,55 @@
+/* eslint-disable func-names */
 const sharp = require('sharp');
 const sanitize = require('sanitize-filename');
 const { promisify } = require('util');
 const imageSize = require('image-size');
+const fs = require('fs');
 
+const stat = promisify(fs.stat);
 const sizeOf = promisify(imageSize);
 
-function getOutputImageName(sourceImage, size) {
+function getOutputImage(sourceImage, size) {
   const extension = sourceImage.split('.').pop();
-  const filenameWithoutExtension = sanitize(sourceImage.substr(0, sourceImage.lastIndexOf('.')) || sourceImage);
-  return `${filenameWithoutExtension}-${size.width}x${size.height}.${extension}`;
+  const name = sanitize(sourceImage.substr(0, sourceImage.lastIndexOf('.')) || sourceImage);
+
+  return {
+    name,
+    extension,
+    width: size.width,
+    height: size.height,
+    formatted() { return `${this.name}-${this.width}x${this.height}.${this.extension}`; },
+    incrementName() {
+      const regex = /(.*)-(\d)$/;
+      const found = this.name.match(regex);
+      if (found === null) {
+        this.name += '-1';
+      } else {
+        const matchedName = found[1];
+        const matchedNumber = found[2];
+        const incremented = Number(matchedNumber) + 1;
+        const newName = `${matchedName}-${incremented}`;
+        this.name = newName;
+      }
+    },
+  };
 }
 
+const getFileSystemSafeFileName = async (outputImage) => {
+  const exists = async (fileName) => {
+    try {
+      await stat(fileName);
+      return true;
+    } catch (err) {
+      return false;
+    }
+  };
+  // eslint-disable-next-line no-await-in-loop
+  while (await exists(outputImage.formatted())) {
+    outputImage.incrementName();
+  }
+  return outputImage.formatted();
+};
+
 module.exports = async function resizeAndSave(config, uploadConfig, file) {
   /**
    * Resize images according to image desired width and height and return sizes
@@ -27,13 +66,14 @@ module.exports = async function resizeAndSave(config, uploadConfig, file) {
     sizes = uploadConfig.imageSizes
       .filter(desiredSize => desiredSize.width < dimensions.width)
       .map(async (desiredSize) => {
-        const outputImageName = getOutputImageName(sourceImage, desiredSize);
+        let outputImage = getOutputImage(sourceImage, desiredSize);
+        outputImage = await getFileSystemSafeFileName(outputImage);
         await sharp(sourceImage)
           .resize(desiredSize.width, desiredSize.height, {
             // would it make sense for this to be set by the uploader?
             position: desiredSize.crop || 'centre',
           })
-          .toFile(outputImageName);
+          .toFile(outputImage.formatted());
         return { ...desiredSize };
       });
   } catch (e) {