Merged esm branch into feature-magic. Ported FileType ops.

src/core/operations/Gunzip.mjs

@@ -0,0 +1,50 @@
+/**
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import zlibAndGzip from "zlibjs/bin/zlib_and_gzip.min";
+
+const Zlib = zlibAndGzip.Zlib;
+
+/**
+ * Gunzip operation
+ */
+class Gunzip extends Operation {
+
+    /**
+     * Gunzip constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Gunzip";
+        this.module = "Compression";
+        this.description = "Decompresses data which has been compressed using the deflate algorithm with gzip headers.";
+        this.inputType = "ArrayBuffer";
+        this.outputType = "ArrayBuffer";
+        this.args = [];
+        this.patterns = [
+            {
+                match: "^\\x1f\\x8b\\x08",
+                flags: "",
+                args: []
+            },
+        ];
+    }
+
+    /**
+     * @param {ArrayBuffer} input
+     * @param {Object[]} args
+     * @returns {File}
+     */
+    run(input, args) {
+        const gunzip = new Zlib.Gunzip(new Uint8Array(input));
+        return new Uint8Array(gunzip.decompress()).buffer;
+    }
+
+}
+
+export default Gunzip;