1 files changed, 168 insertions, 0 deletions
diff --git a/browser/components/downloads/test/unit/test_DownloadsCommon_getMimeInfo.js b/browser/components/downloads/test/unit/test_DownloadsCommon_getMimeInfo.js
new file mode 100644
index 0000000000..3e87fa9ec9
--- /dev/null
+++ b/browser/components/downloads/test/unit/test_DownloadsCommon_getMimeInfo.js
@@ -0,0 +1,168 @@
+const DATA_PDF = atob(
+  "JVBERi0xLjANCjEgMCBvYmo8PC9UeXBlL0NhdGFsb2cvUGFnZXMgMiAwIFI+PmVuZG9iaiAyIDAgb2JqPDwvVHlwZS9QYWdlcy9LaWRzWzMgMCBSXS9Db3VudCAxPj5lbmRvYmogMyAwIG9iajw8L1R5cGUvUGFnZS9NZWRpYUJveFswIDAgMyAzXT4+ZW5kb2JqDQp4cmVmDQowIDQNCjAwMDAwMDAwMDAgNjU1MzUgZg0KMDAwMDAwMDAxMCAwMDAwMCBuDQowMDAwMDAwMDUzIDAwMDAwIG4NCjAwMDAwMDAxMDIgMDAwMDAgbg0KdHJhaWxlcjw8L1NpemUgNC9Sb290IDEgMCBSPj4NCnN0YXJ0eHJlZg0KMTQ5DQolRU9G"
+);
+
+const DOWNLOAD_TEMPLATE = {
+  source: {
+    url: "https://example.com/download",
+  },
+  target: {
+    path: "",
+  },
+  contentType: "text/plain",
+  succeeded: DownloadsCommon.DOWNLOAD_FINISHED,
+  canceled: false,
+  error: null,
+  hasPartialData: false,
+  hasBlockedData: false,
+  startTime: new Date(Date.now() - 1000),
+};
+
+const TESTFILES = {
+  "download-test.txt": "Text file contents\n",
+  "download-test.pdf": DATA_PDF,
+  "download-test.PDF": DATA_PDF,
+  "download-test.xxunknown": "Unknown file contents\n",
+  "download-test": "No extension file contents\n",
+};
+let gPublicList;
+
+add_task(async function test_setup() {
+  let profileDir = Services.dirsvc.get("ProfD", Ci.nsIFile).path;
+  Assert.ok(profileDir, "profileDir: " + profileDir);
+  for (let [filename, contents] of Object.entries(TESTFILES)) {
+    TESTFILES[filename] = await createDownloadedFile(
+      PathUtils.join(gDownloadDir, filename),
+      contents
+    );
+  }
+  gPublicList = await Downloads.getList(Downloads.PUBLIC);
+});
+
+const TESTCASES = [
+  {
+    name: "Check returned value is null when the download did not succeed",
+    testFile: "download-test.txt",
+    contentType: "text/plain",
+    succeeded: false,
+    expected: null,
+  },
+  {
+    name: "Check correct mime-info is returned when download contentType is unambiguous",
+    testFile: "download-test.txt",
+    contentType: "text/plain",
+    expected: {
+      type: "text/plain",
+    },
+  },
+  {
+    name: "Returns correct mime-info from file extension when download contentType is missing",
+    testFile: "download-test.pdf",
+    contentType: undefined,
+    expected: {
+      type: "application/pdf",
+    },
+  },
+  {
+    name: "Returns correct mime-info from file extension case-insensitively",
+    testFile: "download-test.PDF",
+    contentType: undefined,
+    expected: {
+      type: "application/pdf",
+    },
+  },
+  {
+    name: "Returns null when contentType is missing and file extension is unknown",
+    testFile: "download-test.xxunknown",
+    contentType: undefined,
+    expected: null,
+  },
+  {
+    name: "Returns contentType when contentType is ambiguous and file extension is unknown",
+    testFile: "download-test.xxunknown",
+    contentType: "application/octet-stream",
+    expected: {
+      type: "application/octet-stream",
+    },
+  },
+  {
+    name: "Returns contentType when contentType is ambiguous and there is no file extension",
+    testFile: "download-test",
+    contentType: "application/octet-stream",
+    expected: {
+      type: "application/octet-stream",
+    },
+  },
+  {
+    name: "Returns null when there's no contentType and no file extension",
+    testFile: "download-test",
+    contentType: undefined,
+    expected: null,
+  },
+];
+
+// add tests for each of the generic mime-types we recognize,
+// to ensure they prefer the associated mime-type of the target file extension
+for (let type of [
+  "application/octet-stream",
+  "binary/octet-stream",
+  "application/unknown",
+]) {
+  TESTCASES.push({
+    name: `Returns correct mime-info from file extension when contentType is generic (${type})`,
+    testFile: "download-test.pdf",
+    contentType: type,
+    expected: {
+      type: "application/pdf",
+    },
+  });
+}
+
+for (let testData of TESTCASES) {
+  let tmp = {
+    async [testData.name]() {
+      info("testing with: " + JSON.stringify(testData));
+      await test_getMimeInfo_basic_function(testData);
+    },
+  };
+  add_task(tmp[testData.name]);
+}
+
+/**
+ * Sanity test the DownloadsCommon.getMimeInfo method with test parameters
+ */
+async function test_getMimeInfo_basic_function(testData) {
+  let downloadData = {
+    ...DOWNLOAD_TEMPLATE,
+    source: "source" in testData ? testData.source : DOWNLOAD_TEMPLATE.source,
+    succeeded:
+      "succeeded" in testData
+        ? testData.succeeded
+        : DOWNLOAD_TEMPLATE.succeeded,
+    target: TESTFILES[testData.testFile],
+    contentType: testData.contentType,
+  };
+  Assert.ok(downloadData.target instanceof Ci.nsIFile, "target is a nsIFile");
+  let download = await Downloads.createDownload(downloadData);
+  await gPublicList.add(download);
+  await download.refresh();
+
+  Assert.ok(
+    await IOUtils.exists(download.target.path),
+    "The file should actually exist."
+  );
+  let result = await DownloadsCommon.getMimeInfo(download);
+  if (testData.expected) {
+    Assert.equal(
+      result.type,
+      testData.expected.type,
+      "Got expected mimeInfo.type"
+    );
+  } else {
+    Assert.equal(
+      result,
+      null,
+      `Expected null, got object with type: ${result?.type}`
+    );
+  }
+}