Parameters: Encoding: add Encoding Param type

This commit adds the entire Encoding Parameter Type along with it's
associated test cases. See #4

.
Signed-off-by: Mark Stenglein <mark@stengle.in>

src/Parameter/Encoding.ts

+/*
+ * lib-ical
+ * Copyright (C) 2017 Mark Stenglein
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+import Parameter from "./Parameter";
+const b64 = "BASE64";
+const b8 = "8BIT";
+
+/**
+ * Parameter Name:  ENCODING
+ *
+ * Purpose:  To specify an alternate inline encoding for the property
+ *    value.
+ *
+ * Format Definition:  This property parameter is defined by the
+ *    following notation:
+ *
+ *     encodingparam      = "ENCODING" "="
+ *                        ( "8BIT"
+ *        ; "8bit" text encoding is defined in [RFC2045]
+ *                        / "BASE64"
+ *        ; "BASE64" binary encoding format is defined in [RFC4648]
+ *                        )
+ *
+ * Description:  This property parameter identifies the inline encoding
+ *    used in a property value.  The default encoding is "8BIT",
+ *    corresponding to a property value consisting of text.  The
+ *    "BASE64" encoding type corresponds to a property value encoded
+ *    using the "BASE64" encoding defined in [RFC2045].
+ *
+ *    If the value type parameter is ";VALUE=BINARY", then the inline
+ *    encoding parameter MUST be specified with the value
+ *    ";ENCODING=BASE64".
+ *
+ * Example:
+ *
+ *   ATTACH;FMTTYPE=text/plain;ENCODING=BASE64;VALUE=BINARY:TG9yZW
+ *    0gaXBzdW0gZG9sb3Igc2l0IGFtZXQsIGNvbnNlY3RldHVyIGFkaXBpc2ljaW
+ *    BkZXNlcnVudCBtb2xsaXQgYW5pbSBpZCBlc3QgbGFib3J1bS4=
+ *
+ * @author Mark Stenglein <mark@stengle.in>
+ * @since 0.1.0
+ */
+export default class Encoding extends Parameter {
+    private _encoding: string;
+
+    constructor(encoding: string) {
+        super("ENCODING", []);
+        this.encoding = encoding;
+    }
+
+    get encoding(): string {
+        return this._encoding;
+    }
+
+    set encoding(encoding: string) {
+        if (!(encoding === "8bit" || encoding === "BASE64")) {
+            throw new TypeError("Encoding must be 8bit or BASE64");
+        }
+        else {
+            this._encoding = encoding;
+            this.paramValues = [`"${encoding}"`];
+        }
+    }
+
+    public static BASE64 = new Encoding("BASE64");
+    public static BASE8 = new Encoding("8bit");
+}
+

test/Parameter/Encoding.spec.ts

+/*
+* lib-ical
+* Copyright (C) 2017 Mark Stenglein
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU Affero General Public License as published
+* by the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU Affero General Public License for more details.
+*
+* You should have received a copy of the GNU Affero General Public License
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+import Encoding from "../../src/Parameter/Encoding";
+import { expect } from "chai";
+import "mocha";
+
+/**
+ * Test the Encoding class.
+ */
+describe("Encoding:", () => {
+    it("Should exist", () => {
+        expect(Encoding).to.exist;
+    });
+
+    describe("Constructor:", () => {
+        it("Should create an object", () => {
+            const param = new Encoding("BASE64");
+            expect(param).to.exist;
+        });
+
+        it("Should throw exception on invalid encoding", () => {
+            expect(() => {
+                const param = new Encoding("WrongBase");
+            }).to.throw("Encoding must be 8bit or BASE64");
+        });
+    });
+
+    describe("Getter/Setter:", () => {
+        describe("encoding:", () => {
+            it("Should set and read on 8bit", () => {
+                const param = new Encoding("8bit");
+                expect(param.encoding).to.be.equal("8bit");
+            });
+
+            it("Should set and read on BASE64", () => {
+                const param = new Encoding("BASE64");
+                expect(param.encoding).to.be.equal("BASE64");
+            });
+        });
+    });
+
+    describe("Static Vars:", () => {
+        describe("BASE64:", () => {
+            it("Should exist", () => {
+                expect(Encoding.BASE64).to.exist;
+            });
+
+            it("Should have a value of \"BASE64\"", () => {
+                expect(Encoding.BASE64.encoding).to.be.equal("BASE64");
+            });
+        });
+
+        describe("BASE8:", () => {
+            it("Should exist", () => {
+                expect(Encoding.BASE8).to.exist;
+            });
+
+            it("Should have a value of \"8bit\"", () => {
+                expect(Encoding.BASE8.encoding).to.be.equal("8bit");
+            });
+        });
+    });
+
+    describe("Generator:", () => {
+        it("Should correctly generate output", () => {
+            const expected = "ENCODING=\"BASE64\"";
+            expect(Encoding.BASE64.generate()).to.be.equal(expected);
+        });
+    });
+});