Add --clean flag and throw error instead of overwriting existing packed entry.

 - Added the `--clean` command-line flag for unpack operations that will delete the destination directory before unpacking.
 - Throw an error when packing if an entry with the same `_id` would overwrite an entry that had already been packed as part of the same operation.

Author: Fyorl

CHANGELOG.md

@@ -1,3 +1,9 @@
+## 1.0.2
+
+### Improvements
+ - Added the `--clean` command-line flag for unpack operations that will delete the destination directory before unpacking.
+ - Throw an error when packing if an entry with the same `_id` would overwrite an entry that had already been packed as part of the same operation.
+
 ## 1.0.1
 
 ### Fixes

commands/package.mjs

@@ -25,6 +25,7 @@ import { compilePack, extractPack, TYPE_COLLECTION_MAP } from "../lib/package.mj
  * @property {boolean} [nedb]                           Use NeDB instead of ClassicLevel for database operations.
  * @property {boolean} [recursive]                      When packing, recurse down through all directories in the input
  *                                                      directory to find source files.
+ * @property {boolean} [clean]                          When unpacking, delete the destination directory first.
  */
 
 /**
@@ -107,16 +108,23 @@ export function getCommand() {
         type: "boolean"
       });
 
-      yargs.options("nedb", {
+      yargs.option("nedb", {
         describe: "Whether to use NeDB instead of ClassicLevel for database operations.",
         type: "boolean"
       });
 
-      yargs.options("recursive", {
+      yargs.option("recursive", {
+        alias: "r",
         describe: "When packing, recurse down through all directories in the input directory to find source files.",
         type: "boolean"
       });
 
+      yargs.option("clean", {
+        alias: "c",
+        describe: "When unpacking, delete the destination directory first.",
+        type: "boolean"
+      });
+
       return yargs;
     },
     handler: async argv => {
@@ -366,7 +374,7 @@ async function handleUnpack(argv) {
   }
 
   let documentType;
-  const { nedb, yaml } = argv;
+  const { nedb, yaml, clean } = argv;
   if ( nedb ) {
     documentType = determineDocumentType(pack, argv);
     if ( !documentType ) {
@@ -386,7 +394,7 @@ async function handleUnpack(argv) {
   console.log(`[${dbMode}] Unpacking "${chalk.blue(pack)}" to "${chalk.blue(source)}"`);
 
   try {
-    await extractPack(pack, source, { nedb, yaml, documentType, log: true });
+    await extractPack(pack, source, { nedb, yaml, documentType, clean, log: true });
   } catch ( err ) {
     console.error(err);
     process.exitCode = 1;

lib/package.mjs

@@ -44,6 +44,7 @@ import { ClassicLevel } from "classic-level";
  * @property {object} [yamlOptions]             Options to pass to yaml.dump when serializing Documents.
  * @property {JSONOptions} [jsonOptions]        Options to pass to JSON.stringify when serializing Documents.
  * @property {DocumentType} [documentType]      Required only for NeDB packs in order to generate a correct key.
+ * @property {boolean} [clean]                  Delete the destination directory before unpacking.
  * @property {DocumentCollection} [collection]  Required only for NeDB packs in order to generate a correct key. Can be
  *                                              used instead of documentType if known.
  * @property {NameTransformer} [transformName]  A function that is used to generate a filename for the extracted
@@ -206,7 +207,14 @@ async function compileNedb(pack, files, { log, transformEntry }={}) {
 
   // Create a new NeDB Datastore.
   const db = Datastore.create(pack);
-  const packDoc = applyHierarchy(doc => delete doc._key);
+  const seenKeys = new Set();
+  const packDoc = applyHierarchy(doc => {
+    if ( seenKeys.has(doc._key) ) {
+      throw new Error(`An entry with key '${key}' was already packed and would be overwritten by this entry.`);
+    }
+    seenKeys.add(doc._key);
+    delete doc._key;
+  });
 
   // Iterate over all source files, writing them to the DB.
   for ( const file of files ) {
@@ -224,7 +232,7 @@ async function compileNedb(pack, files, { log, transformEntry }={}) {
       await db.insert(doc);
       if ( log ) console.log(`Packed ${chalk.blue(doc._id)}${chalk.blue(doc.name ? ` (${doc.name})` : "")}`);
     } catch ( err ) {
-      if ( log ) console.error(`Failed to parse ${chalk.red(file)}. See error below.`);
+      if ( log ) console.error(`Failed to pack ${chalk.red(file)}. See error below.`);
       throw err;
     }
   }
@@ -255,6 +263,9 @@ async function compileClassicLevel(pack, files, { log, transformEntry }={}) {
   const packDoc = applyHierarchy(async (doc, collection) => {
     const key = doc._key;
     delete doc._key;
+    if ( seenKeys.has(key) ) {
+      throw new Error(`An entry with key '${key}' was already packed and would be overwritten by this entry.`);
+    }
     seenKeys.add(key);
     const value = structuredClone(doc);
     await mapHierarchy(value, collection, d => d._id);
@@ -273,7 +284,7 @@ async function compileClassicLevel(pack, files, { log, transformEntry }={}) {
       await packDoc(doc, collection);
       if ( log ) console.log(`Packed ${chalk.blue(doc._id)}${chalk.blue(doc.name ? ` (${doc.name})` : "")}`);
     } catch ( err ) {
-      if ( log ) console.error(`Failed to parse ${chalk.red(file)}. See error below.`);
+      if ( log ) console.error(`Failed to pack ${chalk.red(file)}. See error below.`);
       throw err;
     }
   }
@@ -323,7 +334,7 @@ async function compactClassicLevel(db) {
  * @returns {Promise<void>}
  */
 export async function extractPack(src, dest, {
-  nedb=false, yaml=false, yamlOptions={}, jsonOptions={}, log=false, documentType, collection, transformEntry,
+  nedb=false, yaml=false, yamlOptions={}, jsonOptions={}, log=false, documentType, collection, clean, transformEntry,
   transformName
 }={}) {
   if ( nedb && (path.extname(src) !== ".db") ) {
@@ -333,6 +344,7 @@ export async function extractPack(src, dest, {
   if ( nedb && !collection ) {
     throw new Error("For NeDB operations, a documentType or collection must be provided.");
   }
+  if ( clean ) fs.rmSync(dest, { force: true, recursive: true, maxRetries: 10 });
   // Create the output directory if it doesn't exist already.
   fs.mkdirSync(dest, { recursive: true });
   if ( nedb ) {