storage: add copyDir

we changed listDir in c44863a9bb to list
a directory . this broke copy for files since a '/' is added when listing
the file.

src/storage/s3.js

@@ -16,6 +16,7 @@ exports = module.exports = {
     exists,
     download,
     copy,
+    copyDir,
 
     listDir,
 
@@ -376,7 +377,7 @@ function encodeCopySource(bucket, path) {
     return `/${bucket}/${output}`;
 }
 
-async function copyFile(apiConfig, fullFromPath, fullToPath, fileSize, progressCallback) {
+async function copyInternal(apiConfig, fullFromPath, fullToPath, fileSize, progressCallback) {
     assert.strictEqual(typeof apiConfig, 'object');
     assert.strictEqual(typeof fullFromPath, 'string');
     assert.strictEqual(typeof fullToPath, 'string');
@@ -477,19 +478,40 @@ async function copy(apiConfig, fromPath, toPath, progressCallback) {
     assert.strictEqual(typeof toPath, 'string');
     assert.strictEqual(typeof progressCallback, 'function');
 
+    const fullFromPath = path.join(apiConfig.prefix, fromPath);
+    const fullToPath = path.join(apiConfig.prefix, toPath);
+
+    const params = {
+        Bucket: apiConfig.bucket,
+        Key: fullFromPath
+    };
+
+    const s3 = createS3Client(apiConfig, { retryStrategy: RETRY_STRATEGY }); // https://docs.aws.amazon.com/sdkref/latest/guide/feature-retry-behavior.html
+    const [error, data] = await safe(s3.headObject(params));
+    if (error && S3_NOT_FOUND(error)) throw new BoxError(BoxError.NOT_FOUND, `Path ${fromPath} not found`);
+    if (error) throw new BoxError(BoxError.EXTERNAL_ERROR, `Error headObject ${fromPath}. ${formatError(error)}`);
+    return await copyInternal(apiConfig, fullFromPath, fullToPath, data.ContentLength, progressCallback);
+}
+
+async function copyDir(apiConfig, fromPath, toPath, progressCallback) {
+    assert.strictEqual(typeof apiConfig, 'object');
+    assert.strictEqual(typeof fromPath, 'string');
+    assert.strictEqual(typeof toPath, 'string');
+    assert.strictEqual(typeof progressCallback, 'function');
+
     let total = 0;
     const concurrency = apiConfig.limits?.copyConcurrency || (apiConfig._provider === 's3' ? 500 : 10);
-    progressCallback({ message: `Copying with concurrency of ${concurrency}` });
+    progressCallback({ message: `Copying ${fromPath} to ${toPath} with concurrency of ${concurrency}` });
 
     let marker = null;
     while (true) {
-        const batch = await listDir(apiConfig, fromPath, 1000, marker); // returned entries are relative to fromPath
+        const batch = await listDir(apiConfig, fromPath, 1000, marker); // returned entries are relative to prefix
         total += batch.entries.length;
         progressCallback({ message: `Copying files from ${total-batch.entries.length}-${total}` });
         await async.eachLimit(batch.entries, concurrency, async (entry) => {
             const fullFromPath = path.join(apiConfig.prefix, entry.path);
             const fullToPath = path.join(apiConfig.prefix, toPath, path.relative(fromPath, entry.path));
-            await copyFile(apiConfig, fullFromPath, fullToPath, entry.size, progressCallback);
+            await copyInternal(apiConfig, fullFromPath, fullToPath, entry.size, progressCallback);
         });
         if (!batch.marker) break;
         marker = batch.marker;
@@ -543,7 +565,7 @@ async function removeDir(apiConfig, remotePathPrefix, progressCallback) {
     let total = 0;
     let marker = null;
     while (true) {
-        const batch = await listDir(apiConfig, remotePathPrefix, 1000, marker); // returns entries relative to remotePathPrefix
+        const batch = await listDir(apiConfig, remotePathPrefix, 1000, marker); // returns entries relative to (root) prefix
 
         const entries = batch.entries;
         total += entries.length;