Rotate module converted to ESM

4 Ops:
- ROT-13
- ROT-47
- Rotate left
- Rotate right
+ module containing common functions

src/core/operations/ROT13.mjs

@@ -0,0 +1,110 @@
+/**
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+
+/**
+ * Default arguments for ROT13 operation
+ */
+const ROT13_AMOUNT = 13,
+    ROT13_LOWERCASE = true,
+    ROT13_UPPERCASE = true;
+
+
+/**
+ * ROT13 operation.
+ */
+class ROT13 extends Operation {
+
+    /**
+     * ROT13 constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "ROT13";
+        this.module = "Default";
+        this.description = "A simple caesar substitution cipher which rotates alphabet characters by the specified amount (default 13).";
+        this.inputType = "byteArray";
+        this.outputType = "byteArray";
+        this.args = [
+            {
+                name: "Rotate lower case chars",
+                type: "boolean",
+                value: ROT13_LOWERCASE
+            },
+            {
+                name: "Rotate upper case chars",
+                type: "boolean",
+                value: ROT13_UPPERCASE
+            },
+            {
+                name: "Amount",
+                type: "number",
+                value: ROT13_AMOUNT
+            },
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {byteArray}
+     */
+    run(input, args) {
+        const output = input,
+            rot13Lowercase = args[0],
+            rot13Upperacse = args[1];
+        let amount = args[2],
+            chr;
+
+        if (amount) {
+            if (amount < 0) {
+                amount = 26 - (Math.abs(amount) % 26);
+            }
+
+            for (let i = 0; i < input.length; i++) {
+                chr = input[i];
+                if (rot13Upperacse && chr >= 65 && chr <= 90) { // Upper case
+                    chr = (chr - 65 + amount) % 26;
+                    output[i] = chr + 65;
+                } else if (rot13Lowercase && chr >= 97 && chr <= 122) { // Lower case
+                    chr = (chr - 97 + amount) % 26;
+                    output[i] = chr + 97;
+                }
+            }
+        }
+        return output;
+    }
+
+    /**
+     * Highlight ROT13
+     *
+     * @param {Object[]} pos
+     * @param {number} pos[].start
+     * @param {number} pos[].end
+     * @param {Object[]} args
+     * @returns {Object[]} pos
+     */
+    highlight(pos, args) {
+        return pos;
+    }
+
+    /**
+     * Highlight ROT13 in reverse
+     *
+     * @param {Object[]} pos
+     * @param {number} pos[].start
+     * @param {number} pos[].end
+     * @param {Object[]} args
+     * @returns {Object[]} pos
+     */
+    highlightReverse(pos, args) {
+        return pos;
+    }
+}
+
+export default ROT13;