Add tests for mediaType

lib/__specs__/main.spec.ts

@@ -1,7 +1,7 @@
 import { describe, it, expect } from "bun:test";
 import { mkConfig } from "../config.ts";
 import { asBlob, generateCsv } from "../generator.ts";
-import { ConfigOptions } from "../types.ts";
+import { ConfigOptions, MediaType } from "../types.ts";
 import { asString } from "../helpers.ts";
 
 const mockData = [
@@ -344,6 +344,27 @@ describe("ExportToCsv", () => {
     expect(firstLine).toBe("Test Csv 2\r");
   });
 
+  it("should allow for custom file extensions", () => {
+    const csvOpts: ConfigOptions = {
+      mediaType: MediaType.csv,
+    };
+    const csvConf = mkConfig(csvOpts);
+
+    const txtOpts: ConfigOptions = {
+      mediaType: MediaType.plain,
+    };
+    const txtConf = mkConfig(txtOpts);
+
+    const tsvOpts: ConfigOptions = {
+      mediaType: MediaType.tsv,
+    };
+    const tsvConf = mkConfig(tsvOpts);
+
+    expect(csvConf.mediaType).toBe(MediaType.csv);
+    expect(txtConf.mediaType).toBe(MediaType.plain);
+    expect(tsvConf.mediaType).toBe(MediaType.tsv);
+  });
+
   describe("asBlob", () => {
     it("should construct a valid blob based on options", async () => {
       const options: ConfigOptions = {