feat(errors): add support for attaching data to errors (#12)

Closes #5

Author: char0n

src/compile.js

@@ -2,6 +2,10 @@ import escape from './escape.js';
 import JSONPointerCompileError from './errors/JSONPointerCompileError.js';
 
 const compile = (referenceTokens) => {
+  if (!Array.isArray(referenceTokens)) {
+    throw new TypeError('Reference tokens must be a list of strings or numbers');
+  }
+
   try {
     if (referenceTokens.length === 0) {
       return '';
@@ -16,8 +20,9 @@ const compile = (referenceTokens) => {
       })
       .join('/')}`;
   } catch (error) {
-    throw new JSONPointerCompileError('Unknown error during JSON Pointer compilation', {
+    throw new JSONPointerCompileError('Unexpected error during JSON Pointer compilation', {
       cause: error,
+      referenceTokens,
     });
   }
 };

src/errors/JSONPointerKeyError.js

@@ -1,8 +1,15 @@
 import JSONPointerEvaluateError from './JSONPointerEvaluateError.js';
 
 class JSONPointerKeyError extends JSONPointerEvaluateError {
-  constructor(referenceToken, options) {
-    super(`Invalid object key: '${referenceToken}' not found`, options);
+  constructor(message, options) {
+    if (
+      typeof message === 'undefined' &&
+      (typeof options?.referenceToken === 'string' || typeof options?.referenceToken === 'number')
+    ) {
+      message = `Invalid object key: '${options.referenceToken}' not found`;
+    }
+
+    super(message, options);
   }
 }
 

src/errors/JSONPointerTypeError.js

@@ -1,11 +1,15 @@
 import JSONPointerEvaluateError from './JSONPointerEvaluateError.js';
 
 class JSONPointerTypeError extends JSONPointerEvaluateError {
-  constructor(referenceToken, options) {
-    super(
-      `Reference token '${referenceToken}' cannot be applied to non object/array value)`,
-      options,
-    );
+  constructor(message, options) {
+    if (
+      typeof message === 'undefined' &&
+      (typeof options?.referenceToken === 'string' || typeof options?.referenceToken === 'number')
+    ) {
+      message = `Reference token '${options.referenceToken}' cannot be applied to non object/array value)`;
+    }
+
+    super(message, options);
   }
 }
 

src/evaluate.js

@@ -15,19 +15,23 @@ const evaluate = (
   const { result, computed: referenceTokens } = parse(jsonPointer, parseOptions);
 
   if (!result.success) {
-    throw new JSONPointerEvaluateError(`Invalid JSON Pointer: ${jsonPointer}`);
+    throw new JSONPointerEvaluateError(`Invalid JSON Pointer: ${jsonPointer}`, {
+      jsonPointer,
+    });
   }
 
-  return referenceTokens.reduce((current, referenceToken) => {
-    if (typeof current !== 'object' || current === null) {
-      throw new JSONPointerTypeError(referenceToken);
-    }
-
+  return referenceTokens.reduce((current, referenceToken, referenceTokenPosition) => {
     if (Array.isArray(current)) {
       if (testArrayDash(referenceToken)) {
         if (strictArrays) {
           throw new JSONPointerIndexError(
             'Invalid array index: "-" always refers to a nonexistent element during evaluation',
+            {
+              jsonPointer,
+              referenceTokens,
+              referenceToken,
+              referenceTokenPosition,
+            },
           );
         } else {
           return current[current.length];
@@ -37,21 +41,47 @@ const evaluate = (
       if (!testArrayIndex(referenceToken) && strictArrays) {
         throw new JSONPointerIndexError(
           `Invalid array index: '${referenceToken}' (MUST be "0", or digits without a leading "0")`,
+          {
+            jsonPointer,
+            referenceTokens,
+            referenceToken,
+            referenceTokenPosition,
+          },
         );
       }
 
       const index = Number(referenceToken);
       if (index >= current.length && strictArrays) {
-        throw new JSONPointerIndexError(`Invalid array index: '${index}' out of bounds`);
+        throw new JSONPointerIndexError(`Invalid array index: '${index}' out of bounds`, {
+          jsonPointer,
+          referenceTokens,
+          referenceToken: index,
+          referenceTokenPosition,
+        });
       }
       return current[index];
     }
 
-    if (!Object.prototype.hasOwnProperty.call(current, referenceToken) && strictObjects) {
-      throw new JSONPointerKeyError(referenceToken);
+    if (typeof current === 'object' && current !== null) {
+      if (!Object.prototype.hasOwnProperty.call(current, referenceToken) && strictObjects) {
+        throw new JSONPointerKeyError(undefined, {
+          jsonPointer,
+          referenceTokens,
+          referenceToken,
+          referenceTokenPosition,
+        });
+      }
+
+      return current[referenceToken];
     }
 
-    return current[referenceToken];
+    throw new JSONPointerTypeError(undefined, {
+      jsonPointer,
+      referenceTokens,
+      referenceToken,
+      referenceTokenPosition,
+      currentValue: current,
+    });
   }, value);
 };
 

src/parse/index.js

@@ -10,7 +10,7 @@ const grammar = new Grammar();
 
 const parse = (jsonPointer, { evaluator = referenceTokenListEvaluator } = {}) => {
   if (typeof jsonPointer !== 'string') {
-    throw new JSONPointerParseError('JSON Pointer must be a string');
+    throw new TypeError('JSON Pointer must be a string');
   }
 
   try {
@@ -31,7 +31,10 @@ const parse = (jsonPointer, { evaluator = referenceTokenListEvaluator } = {}) =>
 
     return { result, ast, computed };
   } catch (error) {
-    throw new JSONPointerParseError('Unknown error during JSON Pointer parsing', { cause: error });
+    throw new JSONPointerParseError('Unexpected error during JSON Pointer parsing', {
+      cause: error,
+      jsonPointer,
+    });
   }
 };
 

src/unescape.js

@@ -1,4 +1,8 @@
 const unescape = (referenceToken) => {
+  if (typeof referenceToken !== 'string') {
+    throw new TypeError('Reference token must be a string');
+  }
+
   return referenceToken.replace(/~1/g, '/').replace(/~0/g, '~');
 };
 

test/compile.js

@@ -40,6 +40,6 @@ describe('compile', function () {
   });
 
   it('should throw error on invalid input', function () {
-    assert.throws(() => compile(null), JSONPointerCompileError);
+    assert.throws(() => compile(null), TypeError);
   });
 });

test/parse.js

@@ -1,6 +1,6 @@
 import { assert } from 'chai';
 
-import { parse, JSONPointerParseError } from '../src/index.js';
+import { parse } from '../src/index.js';
 
 describe('parse', function () {
   context('given valid source string', function () {
@@ -229,10 +229,10 @@ describe('parse', function () {
 
   context('given non-string input', function () {
     specify('should throw error', function () {
-      assert.throws(() => parse([]), JSONPointerParseError);
-      assert.throws(() => parse(1), JSONPointerParseError);
-      assert.throws(() => parse(null), JSONPointerParseError);
-      assert.throws(() => parse(undefined), JSONPointerParseError);
+      assert.throws(() => parse([]), TypeError);
+      assert.throws(() => parse(1), TypeError);
+      assert.throws(() => parse(null), TypeError);
+      assert.throws(() => parse(undefined), TypeError);
     });
   });
 });