diff --git a/src/patcher/content-types-manager.spec.ts b/src/patcher/content-types-manager.spec.ts
new file mode 100644
index 0000000000..0dd8eb38c4
--- /dev/null
+++ b/src/patcher/content-types-manager.spec.ts
@@ -0,0 +1,51 @@
+import { expect } from "chai";
+import { appendContentType } from "./content-types-manager";
+
+describe("content-types-manager", () => {
+    describe("appendContentType", () => {
+        it("should append a content type", () => {
+            const element = {
+                type: "element",
+                name: "xml",
+                elements: [
+                    {
+                        type: "element",
+                        name: "Types",
+                        elements: [
+                            {
+                                type: "element",
+                                name: "Default",
+                            },
+                        ],
+                    },
+                ],
+            };
+            appendContentType(element, "application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml", "docx");
+
+            expect(element).to.deep.equal({
+                elements: [
+                    {
+                        elements: [
+                            {
+                                name: "Default",
+                                type: "element",
+                            },
+                            {
+                                attributes: {
+                                    ContentType: "application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml",
+                                    Extension: "docx",
+                                },
+                                name: "Default",
+                                type: "element",
+                            },
+                        ],
+                        name: "Types",
+                        type: "element",
+                    },
+                ],
+                name: "xml",
+                type: "element",
+            });
+        });
+    });
+});
diff --git a/src/patcher/util.spec.ts b/src/patcher/util.spec.ts
new file mode 100644
index 0000000000..6482298754
--- /dev/null
+++ b/src/patcher/util.spec.ts
@@ -0,0 +1,46 @@
+import { expect } from "chai";
+
+import { createTextElementContents, getFirstLevelElements, patchSpaceAttribute, toJson } from "./util";
+
+describe("util", () => {
+    describe("toJson", () => {
+        it("should return an Element", () => {
+            const output = toJson("<xml></xml>");
+            expect(output).to.be.an("object");
+        });
+    });
+
+    describe("createTextElementContents", () => {
+        it("should return an array of elements", () => {
+            const output = createTextElementContents("hello");
+            expect(output).to.deep.equal([{ type: "text", text: "hello" }]);
+        });
+    });
+
+    describe("patchSpaceAttribute", () => {
+        it("should return an element with the xml:space attribute", () => {
+            const output = patchSpaceAttribute({ type: "element", name: "xml" });
+            expect(output).to.deep.equal({
+                type: "element",
+                name: "xml",
+                attributes: {
+                    "xml:space": "preserve",
+                },
+            });
+        });
+    });
+
+    describe("getFirstLevelElements", () => {
+        it("should return an empty array if no elements are found", () => {
+            const output = toJson("<Relationships></Relationships>");
+            const elements = getFirstLevelElements(output, "Relationships");
+            expect(elements).to.deep.equal([]);
+        });
+
+        it("should return an array if elements are found", () => {
+            const output = toJson("<Relationships><Relationship></Relationship></Relationships>");
+            const elements = getFirstLevelElements(output, "Relationships");
+            expect(elements).to.deep.equal([{ type: "element", name: "Relationship" }]);
+        });
+    });
+});