diff --git a/tests/unit/platforms/modrinth/modrinth-uploader.spec.ts b/tests/unit/platforms/modrinth/modrinth-uploader.spec.ts
new file mode 100644
index 0000000..f0b8156
--- /dev/null
+++ b/tests/unit/platforms/modrinth/modrinth-uploader.spec.ts
@@ -0,0 +1,132 @@
+import { resolve } from "node:path";
+import { readFileSync } from "node:fs";
+import mockFs from "mock-fs";
+import { createFakeFetch } from "../../../utils/fetch-utils";
+import { SecureString } from "@/utils/security/secure-string";
+import { PlatformType } from "@/platforms/platform-type";
+import { FileInfo } from "@/utils/io/file-info";
+import { HttpResponse } from "@/utils/net/http-response";
+import { FormData } from "@/utils/net/form-data";
+import { VersionType } from "@/utils/versioning/version-type";
+import { parseDependency } from "@/dependencies/dependency";
+import { JavaVersion } from "@/utils/java/java-version";
+import { ModrinthUnfeatureMode } from "@/platforms/modrinth/modrinth-unfeature-mode";
+import { ModrinthVersionInit } from "@/platforms/modrinth/modrinth-version";
+import { MODRINTH_API_URL } from "@/platforms/modrinth/modrinth-api-client";
+import { ModrinthUploader } from "@/platforms/modrinth/modrinth-uploader";
+
+const DB = Object.freeze({
+    loaders: Object.freeze(JSON.parse(
+        readFileSync(resolve(__dirname, "../../../content/modrinth/loader.json"), "utf8")
+    )),
+
+    gameVersions: Object.freeze(JSON.parse(
+        readFileSync(resolve(__dirname, "../../../content/modrinth/game_version.json"), "utf8")
+    )),
+});
+
+const MODRINTH_FETCH = createFakeFetch({
+    baseUrl: MODRINTH_API_URL,
+    requiredHeaders: ["Authorization"],
+
+    GET: {
+        "^\\/tag\\/loader": () => DB.loaders,
+
+        "^\\/tag\\/game_version": () => DB.gameVersions,
+
+        "^\\/project\\/foo$": () => ({
+            id: "AAAAAAAA",
+            slug: "foo",
+            project_type: "mod",
+        }),
+
+        "^\\/project\\/AAAAAAAA\\/version\\?featured=true": () => HttpResponse.json([]),
+
+        "^\\/project\\/fabric-api\\/check$": () => ({
+            id: "P7dR8mSH",
+        }),
+    },
+
+    POST: {
+        "^\\/version$": (_, { body }) => {
+            const formData = body as FormData;
+            const data = JSON.parse(formData.get("data") as string) as ModrinthVersionInit;
+
+            expect(data.changelog).toBe("Changelog");
+            expect(data.featured).toBe(true);
+            expect(data.name).toBe("Version v1.0.0");
+            expect(data.project_id).toBe("AAAAAAAA");
+            expect(data.version_number).toBe("1.0.0");
+            expect(data.version_type).toBe(VersionType.ALPHA);
+            expect(data["primary_file"]).toBe("_0");
+            expect(data["file_parts"]).toEqual(["_0"]);
+            expect(data.loaders).toEqual(["fabric"]);
+            expect(data.game_versions).toEqual(["1.18.2"]);
+            expect(data.dependencies).toContainEqual({ project_id: "P7dR8mSH", dependency_type: "required" });
+
+            expect(formData.get("_0")).toHaveProperty("name", "file.txt");
+
+            return {
+                id: "BBBBBBBB",
+                ...data,
+                files: [{
+                    filename: "file.txt",
+                    url: "https://cdn.modrinth.com/data/AAAAAAAA/versions/BBBBBBBB/file.txt",
+                    hashes: { sha1: "sha1" },
+                }],
+            };
+        },
+    },
+});
+
+beforeEach(() => {
+    mockFs({
+        "file.txt": "",
+    });
+});
+
+afterEach(() => {
+    mockFs.restore();
+});
+
+describe("ModrinthUploader", () => {
+    describe("platform", () => {
+        test("returns `PlatformType.MODRINTH`", () => {
+            const uploader = new ModrinthUploader();
+
+            expect(uploader.platform).toBe(PlatformType.MODRINTH);
+        });
+    });
+
+    describe("upload", () => {
+        test("fulfills the specified upload request", async () => {
+            const uploader = new ModrinthUploader({ fetch: MODRINTH_FETCH });
+
+            const report = await uploader.upload({
+                token: SecureString.from("token"),
+                id: "foo",
+                name: "Version v1.0.0",
+                version: "1.0.0",
+                versionType: VersionType.ALPHA,
+                changelog: "Changelog",
+                files: [FileInfo.of("file.txt")],
+                dependencies: [parseDependency("fabric-api@0.75.0(required)")],
+                gameVersions: ["1.18.2"],
+                loaders: ["fabric", "unknown"],
+                java: [JavaVersion.of(17)],
+                unfeatureMode: ModrinthUnfeatureMode.ANY,
+            });
+
+            expect(report).toEqual({
+                id: "AAAAAAAA",
+                version: "BBBBBBBB",
+                url: "https://modrinth.com/mod/foo/version/1.0.0",
+                files: [{
+                    id: "sha1",
+                    name: "file.txt",
+                    url: "https://cdn.modrinth.com/data/AAAAAAAA/versions/BBBBBBBB/file.txt",
+                }],
+            });
+        });
+    });
+});