chore: replace deprecated String.prototype.substr() (#6333)

* chore: replace deprecated String.prototype.substr()

.substr() is deprecated so we replace it with .slice() which works similarily but isn't deprecated

Signed-off-by: Tobias Speicher <rootcommander@gmail.com>

* refactor: add prefer slice lint rule and fix errors

Co-authored-by: erezrokah <erezrokah@users.noreply.github.com>

packages/netlify-cms-core/src/backend.ts

@@ -292,7 +292,7 @@ function prepareMetaPath(path: string, collection: Collection) {
     return path;
   }
   const dir = dirname(path);
-  return dir.substr(collection.get('folder')!.length + 1) || '/';
+  return dir.slice(collection.get('folder')!.length + 1) || '/';
 }
 
 function collectionDepth(collection: Collection) {

packages/netlify-cms-core/src/components/Collection/Entries/EntriesCollection.js

@@ -117,7 +117,7 @@ export class EntriesCollection extends React.Component {
 
 export function filterNestedEntries(path, collectionFolder, entries) {
   const filtered = entries.filter(e => {
-    const entryPath = e.get('path').substring(collectionFolder.length + 1);
+    const entryPath = e.get('path').slice(collectionFolder.length + 1);
     if (!entryPath.startsWith(path)) {
       return false;
     }
@@ -125,7 +125,7 @@ export function filterNestedEntries(path, collectionFolder, entries) {
     // only show immediate children
     if (path) {
       // non root path
-      const trimmed = entryPath.substring(path.length + 1);
+      const trimmed = entryPath.slice(path.length + 1);
       return trimmed.split('/').length === 2;
     } else {
       // root path

packages/netlify-cms-core/src/components/Collection/NestedCollection.js

@@ -144,7 +144,7 @@ export function getTreeData(collection, entries) {
   const rootFolder = '/';
   const entriesObj = entries
     .toJS()
-    .map(e => ({ ...e, path: e.path.substring(collectionFolder.length) }));
+    .map(e => ({ ...e, path: e.path.slice(collectionFolder.length) }));
 
   const dirs = entriesObj.reduce((acc, entry) => {
     let dir = dirname(entry.path);

packages/netlify-cms-core/src/formats/frontmatter.ts

@@ -27,7 +27,7 @@ const parsers = {
     parse: (input: string) => {
       let JSONinput = input.trim();
       // Fix JSON if leading and trailing brackets were trimmed.
-      if (JSONinput.substr(0, 1) !== '{') {
+      if (JSONinput.slice(0, 1) !== '{') {
         JSONinput = '{' + JSONinput + '}';
       }
       return jsonFormatter.fromFile(JSONinput);
@@ -35,7 +35,8 @@ const parsers = {
     stringify: (metadata: object) => {
       let JSONoutput = jsonFormatter.toFile(metadata).trim();
       // Trim leading and trailing brackets.
-      if (JSONoutput.substr(0, 1) === '{' && JSONoutput.substr(-1) === '}') {
+      if (JSONoutput.slice(0, 1) === '{' && JSONoutput.slice(-1) === '}') {
+        // eslint-disable-next-line unicorn/prefer-string-slice
         JSONoutput = JSONoutput.substring(1, JSONoutput.length - 1);
       }
       return JSONoutput;
@@ -54,8 +55,9 @@ const parsers = {
 };
 
 function inferFrontmatterFormat(str: string) {
-  const firstLine = str.substr(0, str.indexOf('\n')).trim();
-  if (firstLine.length > 3 && firstLine.substr(0, 3) === '---') {
+  // eslint-disable-next-line unicorn/prefer-string-slice
+  const firstLine = str.substring(0, str.indexOf('\n')).trim();
+  if (firstLine.length > 3 && firstLine.slice(0, 3) === '---') {
     // No need to infer, `gray-matter` will handle things like `---toml` for us.
     return;
   }
@@ -130,6 +132,7 @@ export class FrontmatterFormatter {
       comments,
       ...format,
     });
+    // eslint-disable-next-line unicorn/prefer-string-slice
     return trimLastLineBreak && file.slice(-1) === '\n' ? file.substring(0, file.length - 1) : file;
   }
 }

packages/netlify-cms-core/src/lib/textHelper.js

@@ -7,5 +7,6 @@ export function stringToRGB(str) {
 
   const c = (hash & 0x00ffffff).toString(16).toUpperCase();
 
+  // eslint-disable-next-line unicorn/prefer-string-slice
   return '00000'.substring(0, 6 - c.length) + c;
 }