Added contract helpers for minter, sg721 & whitelist

utils/isValidFile.ts

@@ -0,0 +1,45 @@
+export const checkFiles = (images: string[], metadata: string[]) => {
+  // Check images length is equal to metadata length
+  if (images.length !== metadata.length) {
+    throw Error('Images files must have matching number of metadata files')
+  }
+
+  function parseFileName(path: string | null): number {
+    // Check file name is not null
+    if (!path) {
+      throw Error('File cannot be null')
+    }
+
+    // Extract fileName from path
+    const fileName = path.match(
+      /([a-zA-Z0-9\s_\\.\-:]+)(.png|.jpg|.gif|.json)?$/i
+    )![1]
+
+    // Check that file name is an Integer
+    if (isNaN(parseInt(fileName, 10))) {
+      throw Error('Filenames must be numbers. Invalid fileName: ' + fileName)
+    }
+    return parseInt(fileName, 10)
+  }
+
+  // We need to ensure that the files are numerically sorted (as opposed to lexicographically)
+  const sortedImages = [...images.map(parseFileName)].sort(function (a, b) {
+    return a - b
+  })
+  const sortedMetadata = [...metadata.map(parseFileName)].sort(function (a, b) {
+    return a - b
+  })
+  let lastValue
+  // Check each image is sequentially named with a number and has a matching metadata file
+  for (let i = 0; i < sortedImages.length; i++) {
+    const image = sortedImages[i]
+    const json = sortedMetadata[i]
+    if (image !== json) {
+      throw Error('Images must have matching JSON files')
+    }
+    if (lastValue && lastValue + 1 !== image) {
+      throw Error('Images must be sequential')
+    }
+    lastValue = image
+  }
+}