create small xml util for editable output

Author: g-harel

internal/xml/index.ts

@@ -0,0 +1,59 @@
+// Generic XML element. None of the implementations' output is sanitized.
+export interface IElement {
+    render(): string;
+}
+
+// Unstructured element that will render as the provided string.
+export class RawElement implements IElement {
+    public text: string;
+
+    public constructor(text: string) {
+        this.text = text;
+    }
+
+    public render(): string {
+        return this.text;
+    }
+}
+
+// Structured element with tag, attributes and children.
+export class Element implements IElement {
+    public tag: string;
+    public attributes: Record<string, string | number>;
+    public children: IElement[];
+
+    public constructor(tag: string, attributes?: Element["attributes"]) {
+        this.tag = tag;
+        this.attributes = attributes || {};
+        this.children = [];
+    }
+
+    public add(child: IElement): Element {
+        this.children.push(child);
+        return this;
+    }
+
+    public render(): string {
+        const attributes = this.renderAttributes();
+        const content = this.renderChildren();
+        return `<${this.tag}${attributes}>${content}</${this.tag}>`;
+    }
+
+    private renderAttributes(): string {
+        const attributes = Object.keys(this.attributes);
+        if (attributes.length === 0) return "";
+        let out = "";
+        for (const attribute of attributes) {
+            out += ` ${attribute}="${this.attributes[attribute]}"`;
+        }
+        return out;
+    }
+
+    private renderChildren(): string {
+        let out = "";
+        for (const child of this.children) {
+            out += child.render();
+        }
+        return out;
+    }
+}

internal/xml/test.ts

@@ -0,0 +1,30 @@
+import {Element, RawElement} from ".";
+
+describe("internal/xml/xml", () => {
+    describe("render", () => {
+        it("should render raw elements", () => {
+            const elem = new RawElement("test");
+            expect(elem.render()).toBe("test");
+        });
+
+        it("should render element tags", () => {
+            const elem = new Element("test");
+            expect(elem.render()).toBe("<test></test>");
+        });
+
+        it("should render element attributes", () => {
+            const elem = new Element("test", {a: 1, "b-c": "d"});
+            expect(elem.render()).toBe('<test a="1" b-c="d"></test>');
+        });
+
+        it("should render element children", () => {
+            const a = new Element("a");
+            const aa = new Element("aa");
+            const ab = new Element("ab");
+            const aba = new RawElement("aba");
+            a.add(aa).add(ab);
+            ab.add(aba);
+            expect(a.render()).toBe('<a><aa></aa><ab>aba</ab></a>');
+        });
+    });
+});