feat: change evaluation now adds case transformation for capture groups

tools/fieldRename.ts

@@ -7,6 +7,7 @@ import { colorize } from "../cli/style.ts";
 import { cliAlert, cliLog, cliPrompt } from "../cli/prompts.ts";
 import { multiSelectMenuInteractive } from "../cli/selectMenu.ts";
 import type { callback, ITool } from "../types.ts";
+import { toCase } from "util/caseManagement.ts";
 
 async function renameFields(
   path: string,
@@ -69,13 +70,42 @@ function applyRename(
   }
 }
 
+/***
+ * Evaluates the change string with the match array
+ *
+ * @description The change string can include the following variables:
+ *
+ * - $<int> - capture groups, indexed from 1
+ * - $<int>i - capture groups, indexed from 1, transforming an integer to an index
+ * - $<int>s - capture groups, indexed from 1, transforming a string to snake case
+ * - $<int>c - capture groups, indexed from 1, transforming a string to camel case
+ * - $<int>l - capture groups, indexed from 1, transforming a string to lower case
+ * - $<int>u - capture groups, indexed from 1, transforming a string to upper case
+ * - $<int>t - capture groups, indexed from 1, transforming a string to title case
+ */
 function evaluateChange(change: string, match: RegExpExecArray) {
   return change.replace(
-    /\$(\d+)(i?)/g,
-    (_, i, indexed) =>
-      indexed
-        ? (parseInt(match[i]) ? (parseInt(match[i]) - 1).toString() : match[i])
-        : match[i],
+    /\$(\d+)([icslut]?)/g,
+    (_, i, indexed) => {
+      switch (indexed) {
+        case "i":
+          return (parseInt(match[i])
+            ? (parseInt(match[i]) - 1).toString()
+            : match[i]);
+        case "s":
+          return toCase(match[i], "snake");
+        case "c":
+          return toCase(match[i], "camel");
+        case "t":
+          return toCase(match[i], "title");
+        case "l":
+          return match[i].toLowerCase();
+        case "u":
+          return match[i].toUpperCase();
+        default:
+          return match[i];
+      }
+    },
   );
 }