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-rw-r--r--ext/mixed/js/object-property-accessor.js125
-rw-r--r--test/test-object-property-accessor.js186
2 files changed, 268 insertions, 43 deletions
diff --git a/ext/mixed/js/object-property-accessor.js b/ext/mixed/js/object-property-accessor.js
index 349037b3..07b8df61 100644
--- a/ext/mixed/js/object-property-accessor.js
+++ b/ext/mixed/js/object-property-accessor.js
@@ -16,15 +16,27 @@
*/
/**
- * Class used to get and set generic properties of an object by using path strings.
+ * Class used to get and mutate generic properties of an object by using path strings.
*/
class ObjectPropertyAccessor {
- constructor(target, setter=null) {
+ /**
+ * Create a new accessor for a specific object.
+ * @param target The object which the getter and mutation methods are applied to.
+ * @returns A new ObjectPropertyAccessor instance.
+ */
+ constructor(target) {
this._target = target;
- this._setter = (typeof setter === 'function' ? setter : null);
}
- getProperty(pathArray, pathLength) {
+ /**
+ * Gets the value at the specified path.
+ * @param pathArray The path to the property on the target object.
+ * @param pathLength How many parts of the pathArray to use.
+ * This parameter is optional and defaults to the length of pathArray.
+ * @returns The value found at the path.
+ * @throws An error is thrown if pathArray is not valid for the target object.
+ */
+ get(pathArray, pathLength) {
let target = this._target;
const ii = typeof pathLength === 'number' ? Math.min(pathArray.length, pathLength) : pathArray.length;
for (let i = 0; i < ii; ++i) {
@@ -37,24 +49,89 @@ class ObjectPropertyAccessor {
return target;
}
- setProperty(pathArray, value) {
- if (pathArray.length === 0) {
- throw new Error('Invalid path');
+ /**
+ * Sets the value at the specified path.
+ * @param pathArray The path to the property on the target object.
+ * @param value The value to assign to the property.
+ * @throws An error is thrown if pathArray is not valid for the target object.
+ */
+ set(pathArray, value) {
+ const ii = pathArray.length - 1;
+ if (ii < 0) { throw new Error('Invalid path'); }
+
+ const target = this.get(pathArray, ii);
+ const key = pathArray[ii];
+ if (!ObjectPropertyAccessor.isValidPropertyType(target, key)) {
+ throw new Error(`Invalid path: ${ObjectPropertyAccessor.getPathString(pathArray)}`);
}
- const target = this.getProperty(pathArray, pathArray.length - 1);
- const key = pathArray[pathArray.length - 1];
+ target[key] = value;
+ }
+
+ /**
+ * Deletes the property of the target object at the specified path.
+ * @param pathArray The path to the property on the target object.
+ * @throws An error is thrown if pathArray is not valid for the target object.
+ */
+ delete(pathArray) {
+ const ii = pathArray.length - 1;
+ if (ii < 0) { throw new Error('Invalid path'); }
+
+ const target = this.get(pathArray, ii);
+ const key = pathArray[ii];
if (!ObjectPropertyAccessor.isValidPropertyType(target, key)) {
throw new Error(`Invalid path: ${ObjectPropertyAccessor.getPathString(pathArray)}`);
}
- if (this._setter !== null) {
- this._setter(target, key, value, pathArray);
- } else {
- target[key] = value;
+ if (Array.isArray(target)) {
+ throw new Error('Invalid type');
+ }
+
+ delete target[key];
+ }
+
+ /**
+ * Swaps two properties of an object or array.
+ * @param pathArray1 The path to the first property on the target object.
+ * @param pathArray2 The path to the second property on the target object.
+ * @throws An error is thrown if pathArray1 or pathArray2 is not valid for the target object,
+ * or if the swap cannot be performed.
+ */
+ swap(pathArray1, pathArray2) {
+ const ii1 = pathArray1.length - 1;
+ if (ii1 < 0) { throw new Error('Invalid path 1'); }
+ const target1 = this.get(pathArray1, ii1);
+ const key1 = pathArray1[ii1];
+ if (!ObjectPropertyAccessor.isValidPropertyType(target1, key1)) { throw new Error(`Invalid path 1: ${ObjectPropertyAccessor.getPathString(pathArray1)}`); }
+
+ const ii2 = pathArray2.length - 1;
+ if (ii2 < 0) { throw new Error('Invalid path 2'); }
+ const target2 = this.get(pathArray2, ii2);
+ const key2 = pathArray2[ii2];
+ if (!ObjectPropertyAccessor.isValidPropertyType(target2, key2)) { throw new Error(`Invalid path 2: ${ObjectPropertyAccessor.getPathString(pathArray2)}`); }
+
+ const value1 = target1[key1];
+ const value2 = target2[key2];
+
+ target1[key1] = value2;
+ try {
+ target2[key2] = value1;
+ } catch (e) {
+ // Revert
+ try {
+ target1[key1] = value1;
+ } catch (e2) {
+ // NOP
+ }
+ throw e;
}
}
+ /**
+ * Converts a path string to a path array.
+ * @param pathArray The path array to convert.
+ * @returns A string representation of pathArray.
+ */
static getPathString(pathArray) {
const regexShort = /^[a-zA-Z_][a-zA-Z0-9_]*$/;
let pathString = '';
@@ -86,6 +163,12 @@ class ObjectPropertyAccessor {
return pathString;
}
+ /**
+ * Converts a path array to a path string. For the most part, the format of this string
+ * matches Javascript's notation for property access.
+ * @param pathString The path string to convert.
+ * @returns An array representation of pathString.
+ */
static getPathArray(pathString) {
const pathArray = [];
let state = 'empty';
@@ -201,6 +284,14 @@ class ObjectPropertyAccessor {
return pathArray;
}
+ /**
+ * Checks whether an object or array has the specified property.
+ * @param object The object to test.
+ * @param property The property to check for existence.
+ * This value should be a string if the object is a non-array object.
+ * For arrays, it should be an integer.
+ * @returns true if the property exists, otherwise false.
+ */
static hasProperty(object, property) {
switch (typeof property) {
case 'string':
@@ -222,6 +313,14 @@ class ObjectPropertyAccessor {
}
}
+ /**
+ * Checks whether a property is valid for the given object
+ * @param object The object to test.
+ * @param property The property to check for existence.
+ * @returns true if the property is correct for the given object type, otherwise false.
+ * For arrays, this means that the property should be a positive integer.
+ * For non-array objects, the property should be a string.
+ */
static isValidPropertyType(object, property) {
switch (typeof property) {
case 'string':
diff --git a/test/test-object-property-accessor.js b/test/test-object-property-accessor.js
index 0773ba6e..1e694946 100644
--- a/test/test-object-property-accessor.js
+++ b/test/test-object-property-accessor.js
@@ -40,29 +40,30 @@ function createTestObject() {
}
-function testGetProperty1() {
- const object = createTestObject();
- const accessor = new ObjectPropertyAccessor(object);
-
+function testGet1() {
const data = [
- [[], object],
- [['0'], object['0']],
- [['value1'], object.value1],
- [['value1', 'value2'], object.value1.value2],
- [['value1', 'value3'], object.value1.value3],
- [['value1', 'value4'], object.value1.value4],
- [['value5'], object.value5],
- [['value5', 0], object.value5[0]],
- [['value5', 1], object.value5[1]],
- [['value5', 2], object.value5[2]]
+ [[], (object) => object],
+ [['0'], (object) => object['0']],
+ [['value1'], (object) => object.value1],
+ [['value1', 'value2'], (object) => object.value1.value2],
+ [['value1', 'value3'], (object) => object.value1.value3],
+ [['value1', 'value4'], (object) => object.value1.value4],
+ [['value5'], (object) => object.value5],
+ [['value5', 0], (object) => object.value5[0]],
+ [['value5', 1], (object) => object.value5[1]],
+ [['value5', 2], (object) => object.value5[2]]
];
- for (const [pathArray, expected] of data) {
- assert.strictEqual(accessor.getProperty(pathArray), expected);
+ for (const [pathArray, getExpected] of data) {
+ const object = createTestObject();
+ const accessor = new ObjectPropertyAccessor(object);
+ const expected = getExpected(object);
+
+ assert.strictEqual(accessor.get(pathArray), expected);
}
}
-function testGetProperty2() {
+function testGet2() {
const object = createTestObject();
const accessor = new ObjectPropertyAccessor(object);
@@ -89,15 +90,12 @@ function testGetProperty2() {
];
for (const [pathArray, message] of data) {
- assert.throws(() => accessor.getProperty(pathArray), {message});
+ assert.throws(() => accessor.get(pathArray), {message});
}
}
-function testSetProperty1() {
- const object = createTestObject();
- const accessor = new ObjectPropertyAccessor(object);
-
+function testSet1() {
const testValue = {};
const data = [
['0'],
@@ -112,17 +110,21 @@ function testSetProperty1() {
];
for (const pathArray of data) {
- accessor.setProperty(pathArray, testValue);
- assert.strictEqual(accessor.getProperty(pathArray), testValue);
+ const object = createTestObject();
+ const accessor = new ObjectPropertyAccessor(object);
+
+ accessor.set(pathArray, testValue);
+ assert.strictEqual(accessor.get(pathArray), testValue);
}
}
-function testSetProperty2() {
+function testSet2() {
const object = createTestObject();
const accessor = new ObjectPropertyAccessor(object);
const testValue = {};
const data = [
+ [[], 'Invalid path'],
[[0], 'Invalid path: [0]'],
[['0', 'invalid'], 'Invalid path: ["0"].invalid'],
[['value1', 'value2', 0], 'Invalid path: value1.value2[0]'],
@@ -137,7 +139,127 @@ function testSetProperty2() {
];
for (const [pathArray, message] of data) {
- assert.throws(() => accessor.setProperty(pathArray, testValue), {message});
+ assert.throws(() => accessor.set(pathArray, testValue), {message});
+ }
+}
+
+
+function testDelete1() {
+ const hasOwn = (object, property) => Object.prototype.hasOwnProperty.call(object, property);
+
+ const data = [
+ [['0'], (object) => !hasOwn(object, '0')],
+ [['value1', 'value2'], (object) => !hasOwn(object.value1, 'value2')],
+ [['value1', 'value3'], (object) => !hasOwn(object.value1, 'value3')],
+ [['value1', 'value4'], (object) => !hasOwn(object.value1, 'value4')],
+ [['value1'], (object) => !hasOwn(object, 'value1')],
+ [['value5'], (object) => !hasOwn(object, 'value5')]
+ ];
+
+ for (const [pathArray, validate] of data) {
+ const object = createTestObject();
+ const accessor = new ObjectPropertyAccessor(object);
+
+ accessor.delete(pathArray);
+ assert.ok(validate(object));
+ }
+}
+
+function testDelete2() {
+ const data = [
+ [[], 'Invalid path'],
+ [[0], 'Invalid path: [0]'],
+ [['0', 'invalid'], 'Invalid path: ["0"].invalid'],
+ [['value1', 'value2', 0], 'Invalid path: value1.value2[0]'],
+ [['value1', 'value3', 'invalid'], 'Invalid path: value1.value3.invalid'],
+ [['value1', 'value4', 'invalid'], 'Invalid path: value1.value4.invalid'],
+ [['value1', 'value4', 0], 'Invalid path: value1.value4[0]'],
+ [['value5', 1, 'invalid'], 'Invalid path: value5[1].invalid'],
+ [['value5', 2, 'invalid'], 'Invalid path: value5[2].invalid'],
+ [['value5', 2, 0], 'Invalid path: value5[2][0]'],
+ [['value5', 2, 0, 'invalid'], 'Invalid path: value5[2][0]'],
+ [['value5', 2.5], 'Invalid index'],
+ [['value5', 0], 'Invalid type'],
+ [['value5', 1], 'Invalid type'],
+ [['value5', 2], 'Invalid type']
+ ];
+
+ for (const [pathArray, message] of data) {
+ const object = createTestObject();
+ const accessor = new ObjectPropertyAccessor(object);
+
+ assert.throws(() => accessor.delete(pathArray), {message});
+ }
+}
+
+
+function testSwap1() {
+ const data = [
+ [['0'], true],
+ [['value1', 'value2'], true],
+ [['value1', 'value3'], true],
+ [['value1', 'value4'], true],
+ [['value1'], false],
+ [['value5', 0], true],
+ [['value5', 1], true],
+ [['value5', 2], true],
+ [['value5'], false]
+ ];
+
+ for (const [pathArray1, compareValues1] of data) {
+ for (const [pathArray2, compareValues2] of data) {
+ const object = createTestObject();
+ const accessor = new ObjectPropertyAccessor(object);
+
+ const value1a = accessor.get(pathArray1);
+ const value2a = accessor.get(pathArray2);
+
+ accessor.swap(pathArray1, pathArray2);
+
+ if (!compareValues1 || !compareValues2) { continue; }
+
+ const value1b = accessor.get(pathArray1);
+ const value2b = accessor.get(pathArray2);
+
+ assert.deepStrictEqual(value1a, value2b);
+ assert.deepStrictEqual(value2a, value1b);
+ }
+ }
+}
+
+function testSwap2() {
+ const data = [
+ [[], [], false, 'Invalid path 1'],
+ [['0'], [], false, 'Invalid path 2'],
+ [[], ['0'], false, 'Invalid path 1'],
+ [[0], ['0'], false, 'Invalid path 1: [0]'],
+ [['0'], [0], false, 'Invalid path 2: [0]']
+ ];
+
+ for (const [pathArray1, pathArray2, checkRevert, message] of data) {
+ const object = createTestObject();
+ const accessor = new ObjectPropertyAccessor(object);
+
+ let value1a;
+ let value2a;
+ if (checkRevert) {
+ try {
+ value1a = accessor.get(pathArray1);
+ value2a = accessor.get(pathArray2);
+ } catch (e) {
+ // NOP
+ }
+ }
+
+ assert.throws(() => accessor.swap(pathArray1, pathArray2), {message});
+
+ if (!checkRevert) { continue; }
+
+ const value1b = accessor.get(pathArray1);
+ const value2b = accessor.get(pathArray2);
+
+ assert.deepStrictEqual(value1a, value1b);
+ assert.deepStrictEqual(value2a, value2b);
}
}
@@ -272,10 +394,14 @@ function testIsValidPropertyType() {
function main() {
- testGetProperty1();
- testGetProperty2();
- testSetProperty1();
- testSetProperty2();
+ testGet1();
+ testGet2();
+ testSet1();
+ testSet2();
+ testDelete1();
+ testDelete2();
+ testSwap1();
+ testSwap2();
testGetPathString1();
testGetPathString2();
testGetPathArray1();