Add fakedom to test UI code, replace all 'innerText' with 'textContent' as it is not compatible with fakedom

test/UI/Popup/TagRenderingQuestion.spec.ts

@@ -0,0 +1,45 @@
+import {describe} from 'mocha'
+import {TagRenderingConfigJson} from "../../../Models/ThemeConfig/Json/TagRenderingConfigJson";
+import TagRenderingConfig from "../../../Models/ThemeConfig/TagRenderingConfig";
+import TagRenderingQuestion from "../../../UI/Popup/TagRenderingQuestion";
+import {UIEventSource} from "../../../Logic/UIEventSource";
+import { expect } from 'chai';
+
+describe("TagRenderingQuestion", () => {
+
+    it("should have a freeform text field with the user defined placeholder", () => {
+
+        const configJson = <TagRenderingConfigJson>{
+            id: "test-tag-rendering",
+            question: "Question?",
+            render: "Rendering {capacity}",
+            freeform: {
+                key: "capacity",
+                type: "pnat",
+                placeholder: "Some user defined placeholder"
+            }
+        }
+        const config = new TagRenderingConfig(configJson, "test")
+        const ui = new TagRenderingQuestion( new UIEventSource<any>({}), config)
+        const html = ui.ConstructElement()
+        expect(html.getElementsByTagName("input")[0]["placeholder"]).eq("Some user defined placeholder")
+    })
+
+    it("should have a freeform text field with a type explanation", () => {
+
+        const configJson = <TagRenderingConfigJson>{
+            id: "test-tag-rendering",
+            question: "Question?",
+            render: "Rendering {capacity}",
+            freeform: {
+                key: "capacity",
+                type: "pnat",
+            }
+        }
+        const config = new TagRenderingConfig(configJson, "test")
+        const ui = new TagRenderingQuestion( new UIEventSource<any>({}), config)
+        const html = ui.ConstructElement()
+        expect(html.getElementsByTagName("input")[0]["placeholder"])
+            .eq("capacity (a positive, whole number)")
+    })
+})