feat: add '--episode-num-offset' option

README.md

@@ -42,6 +42,7 @@ Type values surrounded in square brackets (`[]`) can be used as used as boolean
 | --before                 | String              | false    | Only download episodes before this date (i.e. MM/DD/YYY, inclusive)                                                                                                                                                         |
 | --episode-regex          | String              | false    | Match episode title against provided regex before starting download.                                                                                                                                                        |
 | --episode-digits         | Number              | false    | Minimum number of digits to use for episode numbering (e.g. 3 would generate "001" instead of "1"). Default is 0.                                                                                                           |
+| --episode-num-offset     | Number              | false    | Offset the acquired episode number. Default is 0.                                                                                                                                                                           |
 | --episode-source-order   | String              | false    | Attempted order to extract episode audio URL from RSS feed. Default is "enclosure,link".                                                                                                                                    |
 | --add-mp3-metadata       |                     | false    | Attempts to add a base level of episode metadata to each episode. Recommended only in cases where the original metadata is of poor quality. (**ffmpeg required**)                                                           |
 | --adjust-bitrate         | String (e.g. "48k") | false    | Attempts to adjust bitrate of episodes. (**ffmpeg required**)                                                                                                                                                               |

bin/async.js

@@ -165,6 +165,7 @@ const downloadItemsAsync = async ({
   bitrate,
   episodeTemplate,
   episodeDigits,
+  episodeNumOffset,
   episodeSourceOrder,
   exec,
   feed,
@@ -199,6 +200,7 @@ const downloadItemsAsync = async ({
       ext: audioFileExt,
       template: episodeTemplate,
       width: episodeDigits,
+      offset: episodeNumOffset,
     });
     const outputPodcastPath = _path.resolve(basePath, episodeFilename);
 
@@ -282,6 +284,7 @@ const downloadItemsAsync = async ({
         ext: episodeMetaExt,
         template: episodeTemplate,
         width: episodeDigits,
+        offset: episodeNumOffset,
       });
       const outputEpisodeMetaPath = _path.resolve(basePath, episodeMetaName);
 

bin/bin.js

@@ -32,31 +32,32 @@ import { downloadItemsAsync } from "./async.js";
 setupCommander(commander, process.argv);
 
 const {
-  file,
-  url,
-  outDir,
-  episodeTemplate,
+  after,
+  alwaysPostprocess,
+  attempts,
+  before,
   episodeDigits,
+  episodeNumOffset,
+  episodeRegex,
   episodeSourceOrder,
-  includeMeta,
-  includeEpisodeMeta,
+  episodeTemplate,
+  exec,
+  file,
   includeEpisodeImages,
-  offset,
-  limit,
-  episodeRegex,
-  after,
-  before,
-  override,
-  alwaysPostprocess,
-  reverse,
+  includeEpisodeMeta,
+  includeMeta,
   info,
+  limit,
   list,
-  exec,
   mono,
-  threads,
-  attempts,
+  offset,
+  outDir,
+  override,
   parserConfig,
   proxy,
+  reverse,
+  threads,
+  url,
   addMp3Metadata: addMp3MetadataFlag,
   adjustBitrate: bitrate,
 } = commander;
@@ -206,6 +207,7 @@ const main = async () => {
     after,
     before,
     episodeDigits,
+    episodeNumOffset,
     episodeRegex,
     episodeSourceOrder,
     episodeTemplate,
@@ -229,6 +231,7 @@ const main = async () => {
     bitrate,
     episodeTemplate,
     episodeDigits,
+    episodeNumOffset,
     episodeSourceOrder,
     exec,
     feed,

bin/commander.js

@@ -26,6 +26,16 @@ export const setupCommander = (commander, argv) => {
       createParseNumber({ min: 0, name: "--episode-digits" }),
       1
     )
+    .option(
+      "--episode-num-offset <number>",
+      "offset the acquired episode number",
+      createParseNumber({
+        min: Number.MIN_SAFE_INTEGER,
+        max: Number.MAX_SAFE_INTEGER,
+        name: "--episode-num-offset",
+      }),
+      0
+    )
     .option(
       "--episode-source-order <string>",
       "attempted order to extract episode audio URL from rss feed",

bin/naming.js

@@ -18,8 +18,16 @@ const getSimpleFilename = (name, ext = "") => {
   return `${getSafeName(name, MAX_LENGTH_FILENAME - (ext?.length ?? 0))}${ext}`;
 };
 
-const getItemFilename = ({ item, ext, url, feed, template, width }) => {
-  const episodeNum = feed.items.length - item._originalIndex;
+const getItemFilename = ({
+  item,
+  ext,
+  url,
+  feed,
+  template,
+  width,
+  offset = 0,
+}) => {
+  const episodeNum = feed.items.length - item._originalIndex + offset;
   const formattedPubDate = item.pubDate
     ? dayjs(new Date(item.pubDate)).format("YYYYMMDD")
     : null;

bin/util.js

@@ -15,7 +15,7 @@ const isWin = process.platform === "win32";
   Escape arguments for a shell command used with exec.
   Borrowed from shell-escape: https://github.com/xxorax/node-shell-escape/
   Additionally, @see https://www.robvanderwoude.com/escapechars.php for why
-    we avoid trying tp escape complex sequences in Windows.
+    we avoid trying to escape complex sequences in Windows.
 */
 const escapeArgForShell = (arg) => {
   let result = arg;
@@ -154,6 +154,7 @@ const getItemsToDownload = ({
   before,
   after,
   episodeDigits,
+  episodeNumOffset,
   episodeRegex,
   episodeSourceOrder,
   episodeTemplate,
@@ -243,6 +244,7 @@ const getItemsToDownload = ({
             ext: episodeImageFileExt,
             template: episodeTemplate,
             width: episodeDigits,
+            offset: episodeNumOffset,
           });
 
           const outputImagePath = path.resolve(basePath, episodeImageName);

bin/validate.js

@@ -10,7 +10,6 @@ const createParseNumber = ({ min, max, name, required = true }) => {
 
     try {
       let number = parseInt(value);
-
       if (isNaN(number)) {
         logErrorAndExit(`${name} must be a number`);
       }