Added RenderPDF functionality (#2105)

Co-authored-by: GCHQDeveloper581 <63102987+GCHQDeveloper581@users.noreply.github.com> very basic unit testing

src/core/config/Categories.json

@@ -558,7 +558,7 @@
             "Scatter chart",
             "Series chart",
             "Heatmap chart",
-            "Extract Audio Metadata"
+            "Render PDF"
         ]
     },
     {
@@ -603,4 +603,4 @@
             "Comment"
         ]
     }
-]
+]

src/core/operations/RenderPDF.mjs

@@ -0,0 +1,100 @@
+/**
+ * @author Shailendra [singhshailendra.in]
+ * @copyright Crown Copyright 2017
+ * @license Apache-2.0
+ */
+
+import { fromBase64, toBase64 } from "../lib/Base64.mjs";
+import Operation from "../Operation.mjs";
+import OperationError from "../errors/OperationError.mjs";
+import Utils from "../Utils.mjs";
+
+/**
+ * Render PDF operation
+ */
+class RenderPDF extends Operation {
+
+    /**
+     * RenderPDF constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Render PDF";
+        this.module = "File";
+        this.description = "Displays the input as a PDF preview. Supports Raw and Base64 input formats.";
+        this.inputType = "string";
+        this.outputType = "byteArray";
+        this.presentType = "html";
+        this.args = [
+            {
+                "name": "Input format",
+                "type": "option",
+                "value": ["Base64", "Raw"],
+            }
+        ];
+        this.checks = [
+            {
+                pattern: "^%PDF-",
+                flags: "",
+                args: ["Raw"],
+                useful: true,
+                output: {
+                    mime: "application/pdf"
+                }
+            }
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {byteArray}
+     */
+    run(input, args) {
+        const inputFormat = args[0];
+
+        if (!input.length) return [];
+
+        // Convert input to raw bytes
+        switch (inputFormat) {
+            case "Base64":
+                input = fromBase64(input, undefined, "byteArray");
+                break;
+            case "Raw":
+            default:
+                input = Utils.strToByteArray(input);
+                break;
+        }
+
+        // Check PDF signature
+        if (
+            input[0] !== 0x25 || // %
+            input[1] !== 0x50 || // P
+            input[2] !== 0x44 || // D
+            input[3] !== 0x46    // F
+        ) {
+            throw new OperationError("Input does not appear to be a PDF file.");
+        }
+
+        return input;
+    }
+
+    /**
+     * Displays the PDF using HTML for web apps.
+     *
+     * @param {byteArray} data
+     * @returns {html}
+     */
+    async present(data) {
+        if (!data.length) return "";
+
+        const base64 = toBase64(data);
+        const dataURI = "data:application/pdf;base64," + base64;
+
+        return `<iframe src="${dataURI}" style="width:100%;height:100%;border:1px solid #ccc;"></iframe>`;
+    }
+
+}
+
+export default RenderPDF;

tests/node/tests/nodeApi.mjs

@@ -136,7 +136,7 @@ TestRegister.addApiTests([
 
     it("chef.help: returns multiple results", () => {
         const result = chef.help("base 64");
-        assert.strictEqual(result.length, 13);
+        assert.strictEqual(result.length, 14);
     }),
 
     it("chef.help: looks in description for matches too", () => {

tests/operations/tests/RenderPDF.mjs

@@ -0,0 +1,37 @@
+/**
+ * RenderPDF tests.
+ *
+ * @copyright Crown Copyright 2026
+ * @license Apache-2.0
+ */
+import TestRegister from "../../lib/TestRegister.mjs";
+
+
+TestRegister.addTests([
+    {
+        name: "RenderPDF",
+        input: "Not a PDF",
+        expectedOutput: "Input does not appear to be a PDF file.",
+        recipeConfig: [
+            {
+                op: "Render PDF",
+                args: ["Raw"]
+            },
+        ],
+    },
+    {
+        name: "RenderPDF",
+        input: "",
+        expectedMatch: /^<iframe src="data:application\/pdf;base64,JVBERi0xLjAKCjEgMCBvYmogPDwg/,
+        recipeConfig: [
+            {
+                "op": "Generate QR Code",
+                "args": ["PDF", 1, 1, "Low"]
+            },
+            {
+                "op": "Render PDF",
+                "args": ["Raw"]
+            }
+        ],
+    },
+]);