Tidied up TLV operation and tests

src/core/config/Categories.json

@@ -54,7 +54,7 @@
             "From MessagePack",
             "To Braille",
             "From Braille",
-            "LV Decode"
+            "Parse TLV"
         ]
     },
     {

src/core/lib/TLVParser.mjs

@@ -1,5 +1,8 @@
 /**
+ * Parser for Type-length-value data.
+ *
  * @author gchq77703 []
+ * @author n1474335 [n1474335@gmail.com]
  * @copyright Crown Copyright 2018
  * @license Apache-2.0
  */
@@ -11,12 +14,15 @@ const defaults = {
 };
 
 /**
- * Length Value library
+ * TLVParser library
  */
-export default class LengthValue {
+export default class TLVParser {
 
     /**
-     * LengthValue constructor
+     * TLVParser constructor
+     *
+     * @param {byteArray} input
+     * @param {Object} options
      */
     constructor(input, options) {
         this.input = input;
@@ -24,7 +30,7 @@ export default class LengthValue {
     }
 
     /**
-     * @returns {Number}
+     * @returns {number}
      */
     getLength() {
         if (this.basicEncodingRules) {
@@ -48,13 +54,14 @@ export default class LengthValue {
     }
 
     /**
-     * @param {Number} length
-     * @returns {Number[]}
+     * @param {number} length
+     * @returns {number[]}
      */
     getValue(length) {
         const value = [];
 
         for (let i = 0; i < length; i++) {
+            if (this.location > this.input.length) return value;
             value.push(this.input[this.location]);
             this.location++;
         }
@@ -63,7 +70,7 @@ export default class LengthValue {
     }
 
     /**
-     * @returns {Boolean}
+     * @returns {boolean}
      */
     atEnd() {
         return this.input.length <= this.location;

src/core/operations/LVDecode.mjs

@@ -1,81 +0,0 @@
-/**
- * @author gchq77703 []
- * @copyright Crown Copyright 2018
- * @license Apache-2.0
- */
-
-import Operation from "../Operation";
-import LengthValue from "../lib/LengthValue";
-
-/**
- * From LV Decode operation
- */
-class LVDecode extends Operation {
-
-    /**
-     * LVDecode constructor
-     */
-    constructor() {
-        super();
-
-        this.name = "LV Decode";
-        this.module = "Default";
-        this.description = "Converts a Length-Value (LV) encoded string into a JSON object.  Can optionally include a <code>Key</code> / <code>Type</code> entry.";
-        this.infoURL = "https://wikipedia.org/wiki/KLV";
-        this.inputType = "byteArray";
-        this.outputType = "JSON";
-        this.args = [
-            {
-                name: "Bytes in Key Value",
-                type: "option",
-                value: [
-                    "0 Bytes (No Key)",
-                    "1 Byte",
-                    "2 Bytes",
-                    "4 Bytes"
-                ]
-            },
-            {
-                name: "Bytes in Length Value",
-                type: "option",
-                value: [
-                    "1 Byte",
-                    "2 Bytes",
-                    "4 Bytes"
-                ]
-            },
-            {
-                name: "Use Basic Encoding Rules",
-                type: "boolean"
-            }
-        ];
-    }
-
-    /**
-     * @param {byteArray} input
-     * @param {Object[]} args
-     * @returns {string}
-     */
-    run(input, args) {
-        const bytesInKey = parseInt(args[0].split(" ")[0], 10);
-        const bytesInLength = parseInt(args[1].split(" ")[0], 10);
-        const basicEncodingRules = args[2];
-
-        const lv = new LengthValue(input, { bytesInLength, basicEncodingRules });
-
-        const data = [];
-
-        while (!lv.atEnd()) {
-            const key = bytesInKey ? lv.getValue(bytesInKey) : undefined;
-            const length = lv.getLength();
-            const value = lv.getValue(length);
-
-            data.push({ key, length, value });
-        }
-
-        return data;
-    }
-
-}
-
-export default LVDecode;

src/core/operations/ParseTLV.mjs

@@ -0,0 +1,76 @@
+/**
+ * @author gchq77703 []
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2018
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import TLVParser from "../lib/TLVParser";
+import OperationError from "../errors/OperationError";
+
+/**
+ * Parse TLV operation
+ */
+class ParseTLV extends Operation {
+
+    /**
+     * ParseTLV constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Parse TLV";
+        this.module = "Default";
+        this.description = "Converts a Type-Length-Value (TLV) encoded string into a JSON object.  Can optionally include a <code>Key</code> / <code>Type</code> entry. <br><br>Tags: Key-Length-Value, KLV, Length-Value, LV";
+        this.infoURL = "https://wikipedia.org/wiki/Type-length-value";
+        this.inputType = "byteArray";
+        this.outputType = "JSON";
+        this.args = [
+            {
+                name: "Type/Key size",
+                type: "number",
+                value: 1
+            },
+            {
+                name: "Length size",
+                type: "number",
+                value: 1
+            },
+            {
+                name: "Use BER",
+                type: "boolean",
+                value: false
+            }
+        ];
+    }
+
+    /**
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const [bytesInKey, bytesInLength, basicEncodingRules] = args;
+
+        if (bytesInKey <= 0 && bytesInLength <= 0)
+            throw new OperationError("Type or Length size must be greater than 0");
+
+        const tlv = new TLVParser(input, { bytesInLength, basicEncodingRules });
+
+        const data = [];
+
+        while (!tlv.atEnd()) {
+            const key = bytesInKey ? tlv.getValue(bytesInKey) : undefined;
+            const length = tlv.getLength();
+            const value = tlv.getValue(length);
+
+            data.push({ key, length, value });
+        }
+
+        return data;
+    }
+
+}
+
+export default ParseTLV;