From d791a9b35079be5d25acfcd214ab0917bdd35dfe Mon Sep 17 00:00:00 2001
From: Alex Gleason <alex@alexgleason.me>
Date: Thu, 20 Feb 2025 10:35:27 -0600
Subject: [PATCH] Fix DeepL Response parsing, mock DeepL tests so they can
 always run without API keys

---
 packages/translators/DeepLTranslator.test.ts | 69 ++++++++++++++------
 packages/translators/DeepLTranslator.ts      | 17 ++++-
 packages/translators/schema.test.ts          |  7 ++
 3 files changed, 70 insertions(+), 23 deletions(-)
 create mode 100644 packages/translators/schema.test.ts

diff --git a/packages/translators/DeepLTranslator.test.ts b/packages/translators/DeepLTranslator.test.ts
index ae1565c9..8e37e44b 100644
--- a/packages/translators/DeepLTranslator.test.ts
+++ b/packages/translators/DeepLTranslator.test.ts
@@ -1,21 +1,20 @@
-import { DittoConf } from '@ditto/conf';
 import { detectLanguage } from '@ditto/lang';
 import { assert, assertEquals } from '@std/assert';
 
 import { DeepLTranslator } from './DeepLTranslator.ts';
 
-const {
-  deeplBaseUrl: baseUrl,
-  deeplApiKey: apiKey,
-  translationProvider,
-} = new DittoConf(Deno.env);
-
-const deepl = 'deepl';
-
-Deno.test('DeepL translation with source language omitted', {
-  ignore: !(translationProvider === deepl && apiKey),
-}, async () => {
-  const translator = new DeepLTranslator({ fetch: fetch, baseUrl, apiKey: apiKey! });
+Deno.test('DeepL translation with source language omitted', async () => {
+  const translator = mockDeepL({
+    translations: [
+      { detected_source_language: 'PT', text: 'Good morning friends' },
+      { detected_source_language: 'PT', text: 'My name is Patrick' },
+      {
+        detected_source_language: 'PT',
+        text:
+          'I will live in America, I promise. But first, I should mention that lande is interpreting this text as Italian, how strange.',
+      },
+    ],
+  });
 
   const data = await translator.translate(
     [
@@ -33,10 +32,18 @@ Deno.test('DeepL translation with source language omitted', {
   assertEquals(detectLanguage(data.results[2], 0), 'en');
 });
 
-Deno.test('DeepL translation with source language set', {
-  ignore: !(translationProvider === deepl && apiKey),
-}, async () => {
-  const translator = new DeepLTranslator({ fetch: fetch, baseUrl, apiKey: apiKey as string });
+Deno.test('DeepL translation with source language set', async () => {
+  const translator = mockDeepL({
+    translations: [
+      { detected_source_language: 'PT', text: 'Good morning friends' },
+      { detected_source_language: 'PT', text: 'My name is Patrick' },
+      {
+        detected_source_language: 'PT',
+        text:
+          'I will live in America, I promise. But first, I should mention that lande is interpreting this text as Italian, how strange.',
+      },
+    ],
+  });
 
   const data = await translator.translate(
     [
@@ -54,10 +61,16 @@ Deno.test('DeepL translation with source language set', {
   assertEquals(detectLanguage(data.results[2], 0), 'en');
 });
 
-Deno.test("DeepL translation doesn't alter Nostr URIs", {
-  ignore: !(translationProvider === deepl && apiKey),
-}, async () => {
-  const translator = new DeepLTranslator({ fetch: fetch, baseUrl, apiKey: apiKey as string });
+Deno.test("DeepL translation doesn't alter Nostr URIs", async () => {
+  const translator = mockDeepL({
+    translations: [
+      {
+        detected_source_language: 'EN',
+        text:
+          'Graças ao trabalho de nostr:nprofile1qy2hwumn8ghj7erfw36x7tnsw43z7un9d3shjqpqgujeqakgt7fyp6zjggxhyy7ft623qtcaay5lkc8n8gkry4cvnrzqep59se e nostr:nprofile1qy2hwumn8ghj7erfw36x7tnsw43z7un9d3shjqpqe6tnvlr46lv3lwdu80r07kanhk6jcxy5r07w9umgv9kuhu9dl5hsz44l8s , agora é possível filtrar o feed global por idioma no #Ditto!',
+      },
+    ],
+  });
 
   const patrick =
     'nostr:nprofile1qy2hwumn8ghj7erfw36x7tnsw43z7un9d3shjqpqgujeqakgt7fyp6zjggxhyy7ft623qtcaay5lkc8n8gkry4cvnrzqep59se';
@@ -72,3 +85,17 @@ Deno.test("DeepL translation doesn't alter Nostr URIs", {
   assert(output.includes(patrick));
   assert(output.includes(danidfra));
 });
+
+interface DeepLResponse {
+  translations: {
+    detected_source_language: string;
+    text: string;
+  }[];
+}
+
+function mockDeepL(json: DeepLResponse): DeepLTranslator {
+  return new DeepLTranslator({
+    apiKey: 'deepl',
+    fetch: () => Promise.resolve(new Response(JSON.stringify(json))),
+  });
+}
diff --git a/packages/translators/DeepLTranslator.ts b/packages/translators/DeepLTranslator.ts
index f4b6f918..93da8ad7 100644
--- a/packages/translators/DeepLTranslator.ts
+++ b/packages/translators/DeepLTranslator.ts
@@ -72,7 +72,13 @@ export class DeepLTranslator implements DittoTranslator {
     const json = await response.json();
 
     if (!response.ok) {
-      throw new Error(json['message']);
+      const result = DeepLTranslator.errorSchema().safeParse(json);
+
+      if (result.success) {
+        throw new Error(result.data.message);
+      } else {
+        throw new Error(`Unexpected DeepL error: ${response.statusText} (${response.status})`);
+      }
     }
 
     return DeepLTranslator.schema().parse(json);
@@ -84,10 +90,17 @@ export class DeepLTranslator implements DittoTranslator {
     return z.object({
       translations: z.array(
         z.object({
-          detected_source_language: languageSchema,
+          detected_source_language: z.string().transform((val) => val.toLowerCase()).pipe(languageSchema),
           text: z.string(),
         }),
       ),
     });
   }
+
+  /** DeepL error response schema. */
+  private static errorSchema() {
+    return z.object({
+      message: z.string(),
+    });
+  }
 }
diff --git a/packages/translators/schema.test.ts b/packages/translators/schema.test.ts
new file mode 100644
index 00000000..6d37992c
--- /dev/null
+++ b/packages/translators/schema.test.ts
@@ -0,0 +1,7 @@
+import { assertEquals } from '@std/assert';
+
+import { languageSchema } from './schema.ts';
+
+Deno.test('languageSchema', () => {
+  assertEquals(languageSchema.safeParse('en').success, true);
+});