Return relative path from `writeAttachmentData`

This will make our app more robust to changes in location on the file system.

app/types/attachment/write_attachment_data.js

@@ -1,8 +1,8 @@
 const crypto = require('crypto');
-const FSE = require('fs-extra');
+const fse = require('fs-extra');
 const isArrayBuffer = require('lodash/isArrayBuffer');
 const isString = require('lodash/isString');
-const Path = require('path');
+const path = require('path');
 
 
 //      _writeAttachmentData :: AttachmentsPath ->
@@ -19,10 +19,11 @@ exports.writeAttachmentData = (root) => {
     }
 
     const buffer = Buffer.from(arrayBuffer);
-    const path = Path.join(root, exports._getAttachmentPath());
+    const relativePath = exports._getAttachmentPath();
-    await FSE.ensureFile(path);
+    const absolutePath = path.join(root, relativePath);
-    await FSE.writeFile(path, buffer);
+    await fse.ensureFile(absolutePath);
-    return path;
+    await fse.writeFile(absolutePath, buffer);
+    return relativePath;
   };
 };
 
@@ -36,5 +37,5 @@ exports._getAttachmentName = () => {
 exports._getAttachmentPath = () => {
   const name = exports._getAttachmentName();
   const prefix = name.slice(0, 2);
-  return Path.join(prefix, name);
+  return path.join(prefix, name);
 };

js/modules/types/message.js

@@ -18,6 +18,7 @@ const PRIVATE = 'private';
 //   - Attachments: Sanitize Unicode order override characters.
 // Version 3
 //   - Attachments: Write attachment data to disk and store relative path to it.
+
 const INITIAL_SCHEMA_VERSION = 0;
 
 // Increment this version number every time we add a message schema upgrade

test/app/types/attachment/write_attachment_data_test.js

@@ -1,6 +1,6 @@
-const FSE = require('fs-extra');
+const fse = require('fs-extra');
 const isEqual = require('lodash/isEqual');
-const Path = require('path');
+const path = require('path');
 const stringToArrayBuffer = require('string-to-arraybuffer');
 const tmp = require('tmp');
 const { assert } = require('chai');
@@ -24,17 +24,17 @@ describe('writeAttachmentData', () => {
   });
 
   after(async () => {
-    await FSE.remove(TEMPORARY_DIRECTORY);
+    await fse.remove(TEMPORARY_DIRECTORY);
   });
 
   it('should write file to disk and return path', async () => {
     const input = stringToArrayBuffer('test string');
-    const tempDirectory = Path.join(TEMPORARY_DIRECTORY, 'writeAttachmentData');
+    const tempDirectory = path.join(TEMPORARY_DIRECTORY, 'writeAttachmentData');
 
     const outputPath = await writeAttachmentData(tempDirectory)(input);
-    const output = await FSE.readFile(outputPath);
+    const output = await fse.readFile(path.join(tempDirectory, outputPath));
 
-    assert.lengthOf(Path.relative(tempDirectory, outputPath), PATH_LENGTH);
+    assert.lengthOf(outputPath, PATH_LENGTH);
 
     const inputBuffer = Buffer.from(input);
     assert.isTrue(isEqual(inputBuffer, output));