Add decode and encode operations for URL query strings

These allow converting between URL query strings and JSON.

They are based on the qs NPM package.

Author: baltpeter

package-lock.json

@@ -152,6 +152,7 @@
     "process": "^0.11.10",
     "protobufjs": "^6.11.3",
     "qr-image": "^3.2.0",
+    "qs": "^6.10.3",
     "reflect-metadata": "^0.1.13",
     "scryptsy": "^2.1.0",
     "snackbarjs": "^1.1.0",

package.json

@@ -39,6 +39,8 @@
             "From HTML Entity",
             "URL Encode",
             "URL Decode",
+            "Query String Encode",
+            "Query String Decode",
             "Escape Unicode Characters",
             "Unescape Unicode Characters",
             "Normalise Unicode",

src/core/config/Categories.json

@@ -0,0 +1,74 @@
+/**
+ * @author Benjamin Altpeter [[email protected]]
+ * @copyright Crown Copyright 2022
+ * @license Apache-2.0
+ */
+
+import qs from "qs";
+import Operation from "../Operation.mjs";
+
+/**
+ * Query String Decode operation
+ */
+class QueryStringDecode extends Operation {
+    /**
+     * QueryStringDecode constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Query String Decode";
+        this.module = "URL";
+        this.description =
+            "Converts URL query strings into a JSON representation.<br><br>e.g. <code>a=b&c=1</code> becomes <code>{&quot;a&quot;: &quot;b&quot;, &quot;c&quot;: &quot;1&quot;}</code>";
+        this.infoURL = "https://wikipedia.org/wiki/Query_string";
+        this.inputType = "string";
+        this.outputType = "JSON";
+        this.args = [
+            {
+                name: "Depth",
+                type: "number",
+                value: 5,
+            },
+            {
+                name: "Parameter limit",
+                type: "number",
+                value: 1000,
+            },
+            {
+                name: "Delimiter",
+                type: "string",
+                value: "&",
+            },
+            {
+                name: "Allow dot notation (<code>a.b=c</code>)?",
+                type: "boolean",
+                value: false,
+            },
+            {
+                name: "Allow comma arrays (<code>a=b,c</code>)?",
+                type: "boolean",
+                value: false,
+            },
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {JSON}
+     */
+    run(input, args) {
+        const [depth, parameterLimit, delimiter, allowDots, comma] = args;
+        return qs.parse(input, {
+            depth,
+            delimiter,
+            parameterLimit,
+            allowDots,
+            comma,
+            ignoreQueryPrefix: true,
+        });
+    }
+}
+
+export default QueryStringDecode;

src/core/operations/QueryStringDecode.mjs

@@ -0,0 +1,64 @@
+/**
+ * @author Benjamin Altpeter [[email protected]]
+ * @copyright Crown Copyright 2022
+ * @license Apache-2.0
+ */
+
+import qs from "qs";
+import Operation from "../Operation.mjs";
+
+/**
+ * Query String Encode operation
+ */
+class QueryStringEncode extends Operation {
+    /**
+     * QueryStringEncode constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Query String Encode";
+        this.module = "URL";
+        this.description =
+            "Converts JSON objects into a URL query string representation.<br><br>e.g. <code>{&quot;a&quot;: &quot;b&quot;, &quot;c&quot;: 1}</code> becomes <code>a=b&c=1</code>";
+        this.infoURL = "https://wikipedia.org/wiki/Query_string";
+        this.inputType = "JSON";
+        this.outputType = "string";
+        this.args = [
+            {
+                name: "Array format",
+                type: "option",
+                value: ["brackets", "indices", "repeat", "comma"],
+                defaultIndex: 0,
+            },
+            {
+                name: "Object format",
+                type: "option",
+                value: ["brackets", "dots"],
+                defaultIndex: 0,
+            },
+            {
+                name: "Delimiter",
+                type: "string",
+                value: "&",
+            },
+        ];
+    }
+
+    /**
+     * @param {JSON} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const [arrayFormat, objectFormat, delimiter] = args;
+        return qs.stringify(input, {
+            arrayFormat,
+            delimiter,
+            allowDots: objectFormat === "dots",
+            encode: false,
+        });
+    }
+}
+
+export default QueryStringEncode;

src/core/operations/QueryStringEncode.mjs

@@ -130,6 +130,7 @@ import "./tests/FletcherChecksum.mjs";
 import "./tests/CMAC.mjs";
 import "./tests/AESKeyWrap.mjs";
 import "./tests/Rabbit.mjs";
+import "./tests/QueryString.mjs";
 
 // Cannot test operations that use the File type yet
 // import "./tests/SplitColourChannels.mjs";

tests/operations/index.mjs

@@ -0,0 +1,120 @@
+/**
+ * Query String tests.
+ *
+ * @author Benjamin Altpeter [[email protected]]
+ * @copyright Crown Copyright 2022
+ * @license Apache-2.0
+ */
+
+import TestRegister from "../../lib/TestRegister.mjs";
+
+/**
+ * Small helper for JSON.stringify() with the correct settings.
+ * @param {any} obj An object to stringify
+ * @returns A stringified version of the object, indented by four spaces.
+ */
+const json = (obj) => JSON.stringify(obj, null, 4);
+
+TestRegister.addTests([
+    {
+        name: "Query String Decode simple example (defaults)",
+        input: "?a=b&c=1&d=e;f=g",
+        expectedOutput: json({
+            a: "b",
+            c: "1",
+            d: "e;f=g",
+        }),
+        recipeConfig: [
+            { op: "Query String Decode", args: [5, 1000, "&", false, false] },
+        ],
+    },
+    {
+        name: "Query String Decode arrays and objects (defaults)",
+        input: "a[]=b&a[2]=b&c[d]=e&f=g,h&i.j=k",
+        expectedOutput: json({
+            a: ["b", "b"],
+            c: {
+                d: "e",
+            },
+            f: "g,h",
+            "i.j": "k",
+        }),
+        recipeConfig: [
+            { op: "Query String Decode", args: [5, 1000, "&", false, false] },
+        ],
+    },
+    {
+        name: "Query String Decode arrays and objects (extended)",
+        input: "a[]=b&a[2]=b&c[d]=e&f=g,h&i.j=k",
+        expectedOutput: json({
+            a: ["b", "b"],
+            c: {
+                d: "e",
+            },
+            f: ["g", "h"],
+            i: {
+                j: "k",
+            },
+        }),
+        recipeConfig: [
+            { op: "Query String Decode", args: [5, 1000, "&", true, true] },
+        ],
+    },
+    {
+        name: "Query String Decode delimiter",
+        input: "a=b;c=d",
+        expectedOutput: json({
+            a: "b",
+            c: "d",
+        }),
+        recipeConfig: [
+            { op: "Query String Decode", args: [5, 1000, ";", false, false] },
+        ],
+    },
+    {
+        name: "Query String Decode depth (default)",
+        input: "a[b][c][d][e][f][g][h]=5",
+        expectedOutput: json({
+            a: {
+                b: {
+                    c: {
+                        d: {
+                            e: {
+                                f: {
+                                    "[g][h]": "5",
+                                },
+                            },
+                        },
+                    },
+                },
+            },
+        }),
+        recipeConfig: [
+            { op: "Query String Decode", args: [5, 1000, "&", false, false] },
+        ],
+    },
+    {
+        name: "Query String Decode depth (higher)",
+        input: "a[b][c][d][e][f][g][h]=5",
+        expectedOutput: json({
+            a: {
+                b: {
+                    c: {
+                        d: {
+                            e: {
+                                f: {
+                                    g: {
+                                        h: "5",
+                                    },
+                                },
+                            },
+                        },
+                    },
+                },
+            },
+        }),
+        recipeConfig: [
+            { op: "Query String Decode", args: [7, 1000, "&", false, false] },
+        ],
+    },
+]);