From: Justin Wind <justin.wind+git@gmail.com>
Date: Tue, 14 Mar 2023 23:06:58 +0000 (-0700)
Subject: throw MysteryBoxError instead of generic errors
X-Git-Tag: v2.0.0~1^2~1
X-Git-Url: http://git.squeep.com/?p=squeep-mystery-box;a=commitdiff_plain;h=6c9e123b3c10ef5caafc1a5f352a4705a8579ca9

throw MysteryBoxError instead of generic errors
---

diff --git a/index.js b/index.js
index edc09e1..43cb295 100644
--- a/index.js
+++ b/index.js
@@ -1,7 +1,9 @@
 'use strict';
 
 const MysteryBox = require('./lib/mystery-box');
+const { MysteryBoxError } = require('./lib/errors');
 
 module.exports = {
   MysteryBox,
+  MysteryBoxError,
 };
diff --git a/lib/errors.js b/lib/errors.js
new file mode 100644
index 0000000..ec8d285
--- /dev/null
+++ b/lib/errors.js
@@ -0,0 +1,16 @@
+'use strict';
+
+class MysteryBoxError extends Error {
+  constructor(...args) {
+    super(...args);
+    Error.captureStackTrace(MysteryBoxError);
+  }
+
+  get name() {
+    return this.constructor.name;
+  }
+}
+
+module.exports = {
+  MysteryBoxError,
+};
\ No newline at end of file
diff --git a/lib/mystery-box.js b/lib/mystery-box.js
index 5dcf1b1..ddae815 100644
--- a/lib/mystery-box.js
+++ b/lib/mystery-box.js
@@ -5,6 +5,7 @@ const crypto = require('crypto');
 const zlib = require('zlib');
 const { promisify } = require('util');
 const common = require('./common');
+const { MysteryBoxError } = require('./errors');
 const allVersions = require('./version-parameters');
 const { performance } = require('perf_hooks');
 const { name: packageName, version: packageVersion } = require('../package.json');
@@ -73,7 +74,7 @@ class MysteryBox extends EventEmitter {
     super(...args);
     this.secrets = common.ensureArray(options.encryptionSecret);
     if (!this.secrets.length) {
-      throw new Error('missing encryption secret');
+      throw new MysteryBoxError('missing encryption secret');
     }
 
     // Filter any unavailable algorithms
@@ -93,13 +94,13 @@ class MysteryBox extends EventEmitter {
     // Default to highest
     this.bestVersion = Number(Object.keys(this.versionParameters).sort().pop());
     if (Number.isNaN(this.bestVersion)) {
-      throw new Error('no supported versions available');
+      throw new MysteryBoxError('no supported versions available');
     }
 
     this.Flags = availableFlags;
     this.defaultFlags = 'defaultFlags' in options ? options.defaultFlags : availableFlags.Flate;
     if (this.defaultFlags < 0 || this.defaultFlags > 255) {
-      throw new RangeError('Invalid default flag value');
+      throw new MysteryBoxError('Invalid default flag value');
     }
   }
 
@@ -142,7 +143,7 @@ class MysteryBox extends EventEmitter {
         return scryptAsync(secret, salt, keyBytes);
 
       default:
-        throw new RangeError('unsupported key deriver');
+        throw new MysteryBoxError('unsupported key deriver');
     }
   }
 
@@ -187,7 +188,7 @@ class MysteryBox extends EventEmitter {
       }
     }
     // Nine bytes would be an extravagence.
-    throw new RangeError(`unsupported version header (0x${firstByte.toString(16)})`);
+    throw new MysteryBoxError(`unsupported version header (0x${firstByte.toString(16)})`);
   }
 
 
@@ -211,7 +212,7 @@ class MysteryBox extends EventEmitter {
     }
 
     if (versionBytes > 6) {
-      throw new RangeError(`unsupported version (${versionBytes} bytes)`);
+      throw new MysteryBoxError(`unsupported version (${versionBytes} bytes)`);
     }
 
     // Otherwise, update the masked first byte and parse the rest of the buffer.
@@ -244,7 +245,7 @@ class MysteryBox extends EventEmitter {
     } else if (version <= 0x03ffffffffff) { // 34359738368-4398046511103
       versionBytes = 6;
     } else {
-      throw new RangeError('version too large to encode');
+      throw new MysteryBoxError(`version too large to encode (${version})`);
     }
 
     const buffer = Buffer.alloc(versionBytes);
@@ -296,7 +297,7 @@ class MysteryBox extends EventEmitter {
     const { stats, timingsMs } = MysteryBox._newStats('pack');
 
     if (!(version in this.versionParameters)) {
-      throw new RangeError(`MysteryBox format version ${version} not supported`);
+      throw new MysteryBoxError(`MysteryBox format version ${version} not supported`);
     }
     // eslint-disable-next-line security/detect-object-injection
     const v = this.versionParameters[version];
@@ -320,7 +321,7 @@ class MysteryBox extends EventEmitter {
 
     const { buffer: versionBuffer, versionBytes } = MysteryBox._versionEncode(v.version);
     if (versionBytes !== v.versionBytes) {
-      throw new Error('internal inconsistency, mismatched version byte length');
+      throw new MysteryBoxError('internal inconsistency, mismatched version byte length');
     }
 
     const [iv, salt] = await Promise.all([
@@ -390,7 +391,7 @@ class MysteryBox extends EventEmitter {
     const { stats, timingsMs } = MysteryBox._newStats('unpack');
 
     if (!box) {
-      throw new RangeError('nothing to unpack');
+      throw new MysteryBoxError('nothing to unpack');
     }
 
     const raw = Buffer.from(box, 'base64url');
@@ -398,20 +399,20 @@ class MysteryBox extends EventEmitter {
 
     const { version, versionBytes } = MysteryBox._versionDecode(raw);
     if (!(version in this.versionParameters)) {
-      throw new RangeError('unsupported version');
+      throw new MysteryBoxError(`unsupported version (${version})`);
     }
     // eslint-disable-next-line security/detect-object-injection
     const v = this.versionParameters[version];
 
     if (v.versionBytes !== versionBytes) {
-      throw new Error('internal inconsistency, mismatched version byte length');
+      throw new MysteryBoxError('internal inconsistency, mismatched version byte length');
     }
     offset += v.versionBytes;
     stats.version = version;
 
     const minBytes = v.versionBytes + v.flagsBytes + v.ivBytes + v.saltBytes + v.tagBytes;
     if (raw.length < minBytes) {
-      throw new RangeError('not enough to unpack');
+      throw new MysteryBoxError('not enough to unpack');
     }
 
     const flags = raw.subarray(offset, offset + v.flagsBytes).readUInt8(0);
diff --git a/test/lib/errors.js b/test/lib/errors.js
new file mode 100644
index 0000000..0a31620
--- /dev/null
+++ b/test/lib/errors.js
@@ -0,0 +1,11 @@
+'use strict';
+
+const assert = require('assert');
+const { MysteryBoxError } = require('../../lib/errors');
+
+describe('Errors', function () {
+  it('MysteryBoxError', function () {
+    const e = new MysteryBoxError();
+    assert.strictEqual(e.name, 'MysteryBoxError');
+  });
+}); // Errors
\ No newline at end of file
diff --git a/test/lib/mystery-box.js b/test/lib/mystery-box.js
index dd54a88..e949139 100644
--- a/test/lib/mystery-box.js
+++ b/test/lib/mystery-box.js
@@ -5,6 +5,7 @@
 const assert = require('assert');
 const sinon = require('sinon'); // eslint-disable-line node/no-unpublished-require
 const MysteryBox = require('../../lib/mystery-box');
+const { MysteryBoxError } = require('../../lib/errors');
 const crypto = require('crypto');
 
 function _verbose(mb) {
@@ -53,7 +54,7 @@ describe('MysteryBox', function () {
 
     it('covers bad flags', function () {
       options.defaultFlags = 300;
-      assert.rejects(() => new MysteryBox(options), RangeError);
+      assert.rejects(() => new MysteryBox(options), MysteryBoxError);
     });
 
     it('covers missing ciphers', function () {
@@ -64,7 +65,7 @@ describe('MysteryBox', function () {
 
   describe('_keyFromSecret', function () {
     it('covers invalid', async function () {
-      assert.rejects(() => MysteryBox._keyFromSecret('unknown deriver', 'secret', 'salt', 32), RangeError);
+      assert.rejects(() => MysteryBox._keyFromSecret('unknown deriver', 'secret', 'salt', 32), MysteryBoxError);
     });
   }); // _keyFromSecret
 
@@ -123,7 +124,7 @@ describe('MysteryBox', function () {
       _check(0xfe, 8, 0x00);
     });
     it('covers unsupported', function () {
-      assert.throws(() => MysteryBox._versionHeaderDecode(0xff), RangeError);
+      assert.throws(() => MysteryBox._versionHeaderDecode(0xff), MysteryBoxError);
     });
   }); // _versionHeaderDecode
 
@@ -172,7 +173,7 @@ describe('MysteryBox', function () {
     });
     it('covers too big', function () {
       const buffer = Buffer.from([0xfc, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
-      assert.throws(() => MysteryBox._versionDecode(buffer), RangeError);
+      assert.throws(() => MysteryBox._versionDecode(buffer), MysteryBoxError);
     });
   }); // _versionDecode
 
@@ -226,7 +227,7 @@ describe('MysteryBox', function () {
     });
     it('covers too large', function () {
       const version = 277076930199552;
-      assert.rejects(() => MysteryBox._versionEncode(version), RangeError);
+      assert.rejects(() => MysteryBox._versionEncode(version), MysteryBoxError);
     });
     it('recipricates', function () {
       [
@@ -247,14 +248,14 @@ describe('MysteryBox', function () {
     });
   
     it('covers packing unsupported version', async function () {
-      assert.rejects(() => mb.pack({}, 0), RangeError);
+      assert.rejects(() => mb.pack({}, 0), MysteryBoxError);
     });
 
     it('covers unpacking unsupported version', async function () {
       const badBuffer = Buffer.alloc(128);
       badBuffer.writeUInt8(0, 0); // No such thing as version 0
       const badPayload = badBuffer.toString('base64url');
-      assert.rejects(() => mb.unpack(badPayload), RangeError);
+      assert.rejects(() => mb.unpack(badPayload), MysteryBoxError);
     });
 
     it('encrypts and decrypts default version', async function () {
@@ -386,13 +387,13 @@ describe('MysteryBox', function () {
     });
 
     it('handles undefined', async function () {
-      assert.rejects(() => mb.unpack(), RangeError);
+      assert.rejects(() => mb.unpack(), MysteryBoxError);
     });
 
     it('handles incomplete', async function () {
       this.slow(500);
       const encryptedResult = await mb.pack({ foo: 'bar' });
-      assert.rejects(() => mb.unpack(encryptedResult.slice(0, 6)), RangeError);
+      assert.rejects(() => mb.unpack(encryptedResult.slice(0, 6)), MysteryBoxError);
     });
 
     it('covers internal error, incorrect version byte size, pack', async function () {