From cd41de691a83d592fd3da6a5eea6498134748b62 Mon Sep 17 00:00:00 2001
From: Jarno Rantanen <jarno.rantanen@futurice.com>
Date: Wed, 29 Apr 2020 12:49:47 +0300
Subject: [PATCH] Improve error descriptions around S3 operations and storage.

---
 src/backend/app.ts   | 33 ++++++++++++++++++++-------------
 src/backend/main.ts  | 22 ++++++++++++++++------
 src/index-backend.ts |  2 +-
 3 files changed, 37 insertions(+), 20 deletions(-)

diff --git a/src/backend/app.ts b/src/backend/app.ts
index 44ca2c7d..1ab0d742 100644
--- a/src/backend/app.ts
+++ b/src/backend/app.ts
@@ -58,23 +58,30 @@ export function createS3Client() {
 // S3 fetch helpers
 
 export async function s3GetJsonHelper(s3: AWS.S3, params: AWS.S3.GetObjectRequest) {
-  const result = await s3.getObject(params).promise();
-  if (!result.Body) {
-    throw Error(`Empty JSON in S3 object '${params.Bucket}/${params.Key}`);
+  try {
+    const result = await s3.getObject(params).promise();
+    if (!result.Body) {
+      throw Error(`Empty JSON in S3 object "${params.Bucket}/${params.Key}"`);
+    }
+    return JSON.parse(result.Body.toString('utf-8'));
+  } catch (err) {
+    throw new Error(`Couldn't get JSON from S3 object "${params.Bucket}/${params.Key}" (caused by\n${err}\n)`);
   }
-
-  return JSON.parse(result.Body.toString('utf-8'));
 }
 
 export async function s3PutJsonHelper(s3: AWS.S3, params: AWS.S3.PutObjectRequest) {
-  return await s3
-    .putObject({
-      ...params,
-      ContentType: 'application/json',
-      CacheControl: 'max-age=15',
-      Body: JSON.stringify(params.Body, null, 2),
-    })
-    .promise();
+  try {
+    return await s3
+      .putObject({
+        ...params,
+        ContentType: 'application/json',
+        CacheControl: 'max-age=15',
+        Body: JSON.stringify(params.Body, null, 2),
+      })
+      .promise();
+  } catch (err) {
+    throw new Error(`Couldn't put JSON to S3 object "${params.Bucket}/${params.Key}" (caused by\n${err}\n)`);
+  }
 }
 
 export function createS3Sources(appConstants: AppConstants, s3Client: AWS.S3) {
diff --git a/src/backend/main.ts b/src/backend/main.ts
index 0dc25ef9..8c00926f 100644
--- a/src/backend/main.ts
+++ b/src/backend/main.ts
@@ -33,14 +33,21 @@ export async function storeResponse(
   );
 
   console.log('About to store response', r);
+  const Bucket = app.constants.storageBucket;
+  const Key = getStorageKey(r);
   await app.s3Client
     .putObject({
-      Bucket: app.constants.storageBucket,
-      Key: getStorageKey(r),
+      Bucket,
+      Key,
       Body: JSON.stringify(r),
       ACL: 'private',
     })
-    .promise();
+    .promise()
+    .catch(err =>
+      Promise.reject(
+        new Error(`Couldn't store response to bucket "${Bucket}" under key "${Key}" (caused by\n${err}\n)`),
+      ),
+    );
 }
 
 // Takes a response from the frontend, scrubs it clean, and adds fields required for storing it
@@ -104,9 +111,12 @@ export function hash(input: string, pepper: string) {
 }
 
 export async function obfuscateLowPopulationPostalCode(app: App, postalCode: string) {
-  const lowPopulationPostalCodes = await app.s3Sources.fetchLowPopulationPostalCodes();
-
-  return lowPopulationPostalCodes?.data?.[postalCode] || postalCode;
+  try {
+    const lowPopulationPostalCodes = await app.s3Sources.fetchLowPopulationPostalCodes();
+    return lowPopulationPostalCodes?.data?.[postalCode] || postalCode;
+  } catch (err) {
+    throw new Error(`Couldn't obfuscate low population postal code "${postalCode}" (caused by\n${err}\n)`);
+  }
 }
 
 export async function exportOpenData(app: App) {
diff --git a/src/index-backend.ts b/src/index-backend.ts
index 1f0c8275..43737c05 100644
--- a/src/index-backend.ts
+++ b/src/index-backend.ts
@@ -86,7 +86,7 @@ if (process.argv[0].match(/\/ts-node$/)) {
 
 const response = (statusCode: number, body?: object, logError?: Error) => {
   console.log(`Outgoing response: ${statusCode}`);
-  if (logError) console.error('ERROR (API)', logError);
+  if (logError) console.error(`API request processing failed (caused by\n${logError}\n)`);
   return {
     statusCode,
     body: body ? JSON.stringify(body, null, 2) : '',