Merge pull request #8 from Theodo-UK/feature/s3-content-type

Add toHaveContentTypeEqualTo assertion

README.md

@@ -44,7 +44,7 @@ sls-test-tools is currently being actively maintained, yet is in alpha. Your fee
 
 ### S3
 
-// note these is an async assertion and requires "await"
+Note: these async assertions require "await"
 
 ```
     await expect("BUCKET NAME").toHaveS3ObjectWithNameEqualTo("FILE NAME");
@@ -54,6 +54,15 @@ sls-test-tools is currently being actively maintained, yet is in alpha. Your fee
     await expect("BUCKET NAME").toExistAsS3Bucket();
 ```
 
+```
+    await expect({
+      bucketName: "BUCKET_NAME",
+      objectName: "FILE NAME",
+    }).toHaveContentTypeEqualTo("CONTENT_TYPE");;
+```
+
+where CONTENT_TYPE are [standards MIME types](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types)
+
 ## Helpers
 
 ### General

src/assertions/toHaveContentTypeEqualTo/index.js

@@ -0,0 +1,33 @@
+import { AWSClient } from "../../helpers/general";
+import { testResult } from "../../utils/testResult";
+
+export default {
+  async toHaveContentTypeEqualTo({ bucketName, objectName }, contentType) {
+    const s3 = new AWSClient.S3();
+    const params = {
+      Bucket: bucketName,
+      Key: objectName,
+    };
+
+    let message;
+    try {
+      const object = await s3.getObject(params).promise();
+      if (object.ContentType === contentType) {
+        message = `expected ${objectName} to have content type ${contentType}`;
+        return testResult(message, true);
+      }
+      message = `expected ${objectName} to have content type ${contentType}, but content type found was ${object.ContentType}`;
+      return testResult(message, false);
+    } catch (error) {
+      if (error.code === "NoSuchKey") {
+        message = `expected ${bucketName} to have object with name ${objectName} - not found`;
+        return testResult(message, false);
+      }
+      if (error.code === "NoSuchBucket") {
+        message = `expected ${bucketName} to exist - not found`;
+        return testResult(message, false);
+      }
+      throw error;
+    }
+  },
+};

src/assertions/toHaveEventWithSource/index.js

@@ -1,18 +1,15 @@
+import { testResult } from "../../utils/testResult";
+
 export default {
   toHaveEventWithSource(eventBridgeEvents, expectedSourceName) {
+    let message;
     const receivedSource = JSON.parse(eventBridgeEvents.Messages[0].Body)
       .source;
     if (receivedSource === expectedSourceName) {
-      return {
-        message: () =>
-          `expected sent event to have source ${expectedSourceName}`,
-        pass: true,
-      };
+      message = `expected sent event to have source ${expectedSourceName}`;
+      return testResult(message, true);
     }
-    return {
-      message: () =>
-        `sent event source "${receivedSource}" does not match expected source "${expectedSourceName}"`,
-      pass: false,
-    };
+    message = `sent event source "${receivedSource}" does not match expected source "${expectedSourceName}"`;
+    return testResult(message, false);
   },
 };

src/utils/testResult.js

@@ -0,0 +1,5 @@
+// eslint-disable-next-line import/prefer-default-export
+export const testResult = (message, pass) => ({
+  message: () => message,
+  pass,
+});