feat: added --debug-tar flag

it writes out the intermediate tar file that was used

src/commands/upload.ts

@@ -1,3 +1,6 @@
+import { createWriteStream } from 'fs';
+import { pipeline as pipelineCb } from 'stream';
+import util from 'util';
 import { flags as f } from '@oclif/command';
 import debug from 'debug';
 import { upload } from '../artifacts/api';
@@ -7,11 +10,14 @@ import { Artifact } from '../artifacts/model';
 import { BaseCommand, BaseFlags } from '../command';
 import { produceTarStream } from '../util/tar';
 
+const pipeline = util.promisify(pipelineCb);
+
 const log = debug('monofo:cmd:upload');
 
 interface UploadFlags extends BaseFlags {
   'files-from'?: string;
   null: boolean;
+  'debug-tar'?: string;
 }
 
 interface UploadArgs {
@@ -59,6 +65,10 @@ locally cached
       dependsOn: ['files-from'],
       description: "If given, the list of files is expected to be null-separated (a la find's -print0)",
     }),
+    'debug-tar': f.string({
+      char: 'T',
+      description: 'A path to write the uncompressed resulting tar file to (as a debug measure)',
+    }),
   };
 
   static override args = [
@@ -106,6 +116,12 @@ locally cached
 
     const tarStream = produceTarStream(paths);
 
+    if (flags['debug-tar']) {
+      log(`Writing debug tar to ${flags['debug-tar']}`);
+      await pipeline(tarStream, createWriteStream(flags['debug-tar']));
+      log('Finished writing debug tar');
+    }
+
     log(`Deflating archive`);
     await deflator(artifact, tarStream);
     log(`Archive deflated at ${args.output}`);

src/util/tar.ts

@@ -69,10 +69,26 @@ export function depthSort(paths: string[]): string[] {
     .sort((p1, p2) => p1.split(path.sep).length - p2.split(path.sep).length);
 }
 
+/**
+ * number of ch occurances in str without .split() (less allocations)
+ */
+const charCount = (haystack: string, needleChar: string) =>
+  _.sumBy(haystack, (x: string) => (x === needleChar ? 1 : 0));
+
 export function produceTarStream(paths: PathsToPack) {
   const prefixMatch: string[] = Object.entries(paths)
     .filter(([, { recurse }]) => recurse)
-    .map(([k]) => (k.startsWith('./') ? k.slice(2) : k));
+    .map(([pathKey]) => {
+      const toPackPath = pathKey.startsWith('./') ? pathKey.slice(2) : pathKey; // without initial ./ prefix for matching purposes
+      const depth = charCount(pathKey, path.sep);
+      return { toPackPath, depth };
+    })
+    .sort()
+    .sort((a, b): number => a.depth - b.depth)
+    .map(({ toPackPath }) => toPackPath);
+
+  // These are sorted so that lower depths occur first in the array
+  // This is convenient for monorepo setups, where more common dependencies are usually lower in the tree
 
   const exactMatch: Record<string, boolean> = Object.fromEntries(
     Object.entries(paths)
@@ -82,7 +98,7 @@ export function produceTarStream(paths: PathsToPack) {
 
   return pack('.', {
     ignore: (name: string): boolean => {
-      return !(name in exactMatch) && prefixMatch.find((prefix) => name.startsWith(prefix)) === undefined;
+      return !(name in exactMatch || prefixMatch.find((prefix) => name.startsWith(prefix)));
     },
   });
 }