Merge pull request #406 from toasted-nutbread/object-property-accessor

Object property accessor

3 files changed, 534 insertions, 1 deletions

diff --git a/ext/mixed/js/object-property-accessor.js b/ext/mixed/js/object-property-accessor.js
new file mode 100644
index 00000000..108afc0d
--- /dev/null
+++ b/ext/mixed/js/object-property-accessor.js
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2016-2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Class used to get and set generic properties of an object by using path strings.
+ */
+class ObjectPropertyAccessor {
+    constructor(target, setter=null) {
+        this._target = target;
+        this._setter = (typeof setter === 'function' ? setter : null);
+    }
+
+    getProperty(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) {
+            const key = pathArray[i];
+            if (!ObjectPropertyAccessor.hasProperty(target, key)) {
+                throw new Error(`Invalid path: ${ObjectPropertyAccessor.getPathString(pathArray.slice(0, i + 1))}`);
+            }
+            target = target[key];
+        }
+        return target;
+    }
+
+    setProperty(pathArray, value) {
+        if (pathArray.length === 0) {
+            throw new Error('Invalid path');
+        }
+
+        const target = this.getProperty(pathArray, pathArray.length - 1);
+        const key = pathArray[pathArray.length - 1];
+        if (!ObjectPropertyAccessor.isValidPropertyType(target, key)) {
+            throw new Error(`Invalid path: ${ObjectPropertyAccessor.getPathString(pathArray)}`);
+        }
+
+        if (this._setter !== null) {
+            this._setter(target, key, value, pathArray);
+        } else {
+            target[key] = value;
+        }
+    }
+
+    static getPathString(pathArray) {
+        const regexShort = /^[a-zA-Z_][a-zA-Z0-9_]*$/;
+        let pathString = '';
+        let first = true;
+        for (let part of pathArray) {
+            switch (typeof part) {
+                case 'number':
+                    if (Math.floor(part) !== part || part < 0) {
+                        throw new Error('Invalid index');
+                    }
+                    part = `[${part}]`;
+                    break;
+                case 'string':
+                    if (!regexShort.test(part)) {
+                        const escapedPart = part.replace(/["\\]/g, '\\$&');
+                        part = `["${escapedPart}"]`;
+                    } else {
+                        if (!first) {
+                            part = `.${part}`;
+                        }
+                    }
+                    break;
+                default:
+                    throw new Error(`Invalid type: ${typeof part}`);
+            }
+            pathString += part;
+            first = false;
+        }
+        return pathString;
+    }
+
+    static getPathArray(pathString) {
+        const pathArray = [];
+        let state = 'empty';
+        let quote = 0;
+        let value = '';
+        let escaped = false;
+        for (const c of pathString) {
+            const v = c.codePointAt(0);
+            switch (state) {
+                case 'empty': // Empty
+                case 'id-start': // Expecting identifier start
+                    if (v === 0x5b) { // '['
+                        if (state === 'id-start') {
+                            throw new Error(`Unexpected character: ${c}`);
+                        }
+                        state = 'open-bracket';
+                    } else if (
+                        (v >= 0x41 && v <= 0x5a) || // ['A', 'Z']
+                        (v >= 0x61 && v <= 0x7a) || // ['a', 'z']
+                        v === 0x5f // '_'
+                    ) {
+                        state = 'id';
+                        value += c;
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'id': // Identifier
+                    if (
+                        (v >= 0x41 && v <= 0x5a) || // ['A', 'Z']
+                        (v >= 0x61 && v <= 0x7a) || // ['a', 'z']
+                        (v >= 0x30 && v <= 0x39) || // ['0', '9']
+                        v === 0x5f // '_'
+                    ) {
+                        value += c;
+                    } else if (v === 0x5b) { // '['
+                        pathArray.push(value);
+                        value = '';
+                        state = 'open-bracket';
+                    } else if (v === 0x2e) { // '.'
+                        pathArray.push(value);
+                        value = '';
+                        state = 'id-start';
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'open-bracket': // Open bracket
+                    if (v === 0x22 || v === 0x27) { // '"' or '\''
+                        quote = v;
+                        state = 'string';
+                    } else if (v >= 0x30 && v <= 0x39) { // ['0', '9']
+                        state = 'number';
+                        value += c;
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'string': // Quoted string
+                    if (escaped) {
+                        value += c;
+                        escaped = false;
+                    } else if (v === 0x5c) { // '\\'
+                        escaped = true;
+                    } else if (v !== quote) {
+                        value += c;
+                    } else {
+                        state = 'close-bracket';
+                    }
+                    break;
+                case 'number': // Number
+                    if (v >= 0x30 && v <= 0x39) { // ['0', '9']
+                        value += c;
+                    } else if (v === 0x5d) { // ']'
+                        pathArray.push(Number.parseInt(value, 10));
+                        value = '';
+                        state = 'next';
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'close-bracket': // Expecting closing bracket after quoted string
+                    if (v === 0x5d) { // ']'
+                        pathArray.push(value);
+                        value = '';
+                        state = 'next';
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+                case 'next': // Expecting . or [
+                    if (v === 0x5b) { // '['
+                        state = 'open-bracket';
+                    } else if (v === 0x2e) { // '.'
+                        state = 'id-start';
+                    } else {
+                        throw new Error(`Unexpected character: ${c}`);
+                    }
+                    break;
+            }
+        }
+        switch (state) {
+            case 'empty':
+            case 'next':
+                break;
+            case 'id':
+                pathArray.push(value);
+                value = '';
+                break;
+            default:
+                throw new Error('Path not terminated correctly');
+        }
+        return pathArray;
+    }
+
+    static hasProperty(object, property) {
+        switch (typeof property) {
+            case 'string':
+                return (
+                    typeof object === 'object' &&
+                    object !== null &&
+                    !Array.isArray(object) &&
+                    Object.prototype.hasOwnProperty.call(object, property)
+                );
+            case 'number':
+                return (
+                    Array.isArray(object) &&
+                    property >= 0 &&
+                    property < object.length &&
+                    property === Math.floor(property)
+                );
+            default:
+                return false;
+        }
+    }
+
+    static isValidPropertyType(object, property) {
+        switch (typeof property) {
+            case 'string':
+                return (
+                    typeof object === 'object' &&
+                    object !== null &&
+                    !Array.isArray(object)
+                );
+            case 'number':
+                return (
+                    Array.isArray(object) &&
+                    property >= 0 &&
+                    property === Math.floor(property)
+                );
+            default:
+                return false;
+        }
+    }
+}
diff --git a/package.json b/package.json
index eb449ea9..23f0eb25 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,7 @@
     "scripts": {
         "test": "npm run test-lint && npm run test-code",
         "test-lint": "eslint . && node ./test/lint/global-declarations.js",
-        "test-code": "node ./test/test-schema.js && node ./test/test-dictionary.js && node ./test/test-database.js && node ./test/test-document.js"
+        "test-code": "node ./test/test-schema.js && node ./test/test-dictionary.js && node ./test/test-database.js && node ./test/test-document.js && node ./test/test-object-property-accessor.js"
     },
     "repository": {
         "type": "git",
diff --git a/test/test-object-property-accessor.js b/test/test-object-property-accessor.js
new file mode 100644
index 00000000..47d2e451
--- /dev/null
+++ b/test/test-object-property-accessor.js
@@ -0,0 +1,289 @@
+/*
+ * Copyright (C) 2020  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+const assert = require('assert');
+const {VM} = require('./yomichan-vm');
+
+const vm = new VM({});
+vm.execute('mixed/js/object-property-accessor.js');
+const ObjectPropertyAccessor = vm.get('ObjectPropertyAccessor');
+
+
+function createTestObject() {
+    return {
+        0: null,
+        value1: {
+            value2: {},
+            value3: [],
+            value4: null
+        },
+        value5: [
+            {},
+            [],
+            null
+        ]
+    };
+}
+
+
+function testGetProperty1() {
+    const object = createTestObject();
+    const accessor = new ObjectPropertyAccessor(object);
+
+    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]]
+    ];
+
+    for (const [pathArray, expected] of data) {
+        assert.strictEqual(accessor.getProperty(pathArray), expected);
+    }
+}
+
+function testGetProperty2() {
+    const object = createTestObject();
+    const accessor = new ObjectPropertyAccessor(object);
+
+    const data = [
+        [[0], 'Invalid path: [0]'],
+        [['0', 'invalid'], 'Invalid path: ["0"].invalid'],
+        [['invalid'], 'Invalid path: invalid'],
+        [['value1', 'invalid'], 'Invalid path: value1.invalid'],
+        [['value1', 'value2', 'invalid'], 'Invalid path: value1.value2.invalid'],
+        [['value1', 'value2', 0], 'Invalid path: value1.value2[0]'],
+        [['value1', 'value3', 'invalid'], 'Invalid path: value1.value3.invalid'],
+        [['value1', 'value3', 0], 'Invalid path: value1.value3[0]'],
+        [['value1', 'value4', 'invalid'], 'Invalid path: value1.value4.invalid'],
+        [['value1', 'value4', 0], 'Invalid path: value1.value4[0]'],
+        [['value5', 'length'], 'Invalid path: value5.length'],
+        [['value5', 0, 'invalid'], 'Invalid path: value5[0].invalid'],
+        [['value5', 0, 0], 'Invalid path: value5[0][0]'],
+        [['value5', 1, 'invalid'], 'Invalid path: value5[1].invalid'],
+        [['value5', 1, 0], 'Invalid path: value5[1][0]'],
+        [['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']
+    ];
+
+    for (const [pathArray, message] of data) {
+        assert.throws(() => accessor.getProperty(pathArray), {message});
+    }
+}
+
+
+function testSetProperty1() {
+    const object = createTestObject();
+    const accessor = new ObjectPropertyAccessor(object);
+
+    const testValue = {};
+    const data = [
+        ['0'],
+        ['value1', 'value2'],
+        ['value1', 'value3'],
+        ['value1', 'value4'],
+        ['value1'],
+        ['value5', 0],
+        ['value5', 1],
+        ['value5', 2],
+        ['value5']
+    ];
+
+    for (const pathArray of data) {
+        accessor.setProperty(pathArray, testValue);
+        assert.strictEqual(accessor.getProperty(pathArray), testValue);
+    }
+}
+
+function testSetProperty2() {
+    const object = createTestObject();
+    const accessor = new ObjectPropertyAccessor(object);
+
+    const testValue = {};
+    const data = [
+        [[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']
+    ];
+
+    for (const [pathArray, message] of data) {
+        assert.throws(() => accessor.setProperty(pathArray, testValue), {message});
+    }
+}
+
+
+function testGetPathString1() {
+    const data = [
+        [[], ''],
+        [[0], '[0]'],
+        [['escape\\'], '["escape\\\\"]'],
+        [['\'quote\''], '["\'quote\'"]'],
+        [['"quote"'], '["\\"quote\\""]'],
+        [['part1', 'part2'], 'part1.part2'],
+        [['part1', 'part2', 3], 'part1.part2[3]'],
+        [['part1', 'part2', '3'], 'part1.part2["3"]'],
+        [['part1', 'part2', '3part'], 'part1.part2["3part"]'],
+        [['part1', 'part2', '3part', 'part4'], 'part1.part2["3part"].part4'],
+        [['part1', 'part2', '3part', '4part'], 'part1.part2["3part"]["4part"]']
+    ];
+
+    for (const [pathArray, expected] of data) {
+        assert.strictEqual(ObjectPropertyAccessor.getPathString(pathArray), expected);
+    }
+}
+
+function testGetPathString2() {
+    const data = [
+        [[1.5], 'Invalid index'],
+        [[null], 'Invalid type: object']
+    ];
+
+    for (const [pathArray, message] of data) {
+        assert.throws(() => ObjectPropertyAccessor.getPathString(pathArray), {message});
+    }
+}
+
+
+function testGetPathArray1() {
+    const data = [
+        ['', []],
+        ['[0]', [0]],
+        ['["escape\\\\"]', ['escape\\']],
+        ['["\'quote\'"]', ['\'quote\'']],
+        ['["\\"quote\\""]', ['"quote"']],
+        ['part1.part2', ['part1', 'part2']],
+        ['part1.part2[3]', ['part1', 'part2', 3]],
+        ['part1.part2["3"]', ['part1', 'part2', '3']],
+        ['part1.part2[\'3\']', ['part1', 'part2', '3']],
+        ['part1.part2["3part"]', ['part1', 'part2', '3part']],
+        ['part1.part2[\'3part\']', ['part1', 'part2', '3part']],
+        ['part1.part2["3part"].part4', ['part1', 'part2', '3part', 'part4']],
+        ['part1.part2[\'3part\'].part4', ['part1', 'part2', '3part', 'part4']],
+        ['part1.part2["3part"]["4part"]', ['part1', 'part2', '3part', '4part']],
+        ['part1.part2[\'3part\'][\'4part\']', ['part1', 'part2', '3part', '4part']]
+    ];
+
+    for (const [pathString, expected] of data) {
+        vm.assert.deepStrictEqual(ObjectPropertyAccessor.getPathArray(pathString), expected);
+    }
+}
+
+function testGetPathArray2() {
+    const data = [
+        ['?', 'Unexpected character: ?'],
+        ['.', 'Unexpected character: .'],
+        ['0', 'Unexpected character: 0'],
+        ['part1.[0]', 'Unexpected character: ['],
+        ['part1?', 'Unexpected character: ?'],
+        ['[part1]', 'Unexpected character: p'],
+        ['[0a]', 'Unexpected character: a'],
+        ['["part1"x]', 'Unexpected character: x'],
+        ['[\'part1\'x]', 'Unexpected character: x'],
+        ['["part1"]x', 'Unexpected character: x'],
+        ['[\'part1\']x', 'Unexpected character: x'],
+        ['part1..part2', 'Unexpected character: .'],
+
+        ['[', 'Path not terminated correctly'],
+        ['part1.', 'Path not terminated correctly'],
+        ['part1[', 'Path not terminated correctly'],
+        ['part1["', 'Path not terminated correctly'],
+        ['part1[\'', 'Path not terminated correctly'],
+        ['part1[""', 'Path not terminated correctly'],
+        ['part1[\'\'', 'Path not terminated correctly'],
+        ['part1[0', 'Path not terminated correctly'],
+        ['part1[0].', 'Path not terminated correctly']
+    ];
+
+    for (const [pathString, message] of data) {
+        assert.throws(() => ObjectPropertyAccessor.getPathArray(pathString), {message});
+    }
+}
+
+
+function testHasProperty() {
+    const data = [
+        [{}, 'invalid', false],
+        [{}, 0, false],
+        [{valid: 0}, 'valid', true],
+        [{null: 0}, null, false],
+        [[], 'invalid', false],
+        [[], 0, false],
+        [[0], 0, true],
+        [[0], null, false],
+        ['string', 0, false],
+        ['string', 'length', false],
+        ['string', null, false]
+    ];
+
+    for (const [object, property, expected] of data) {
+        assert.strictEqual(ObjectPropertyAccessor.hasProperty(object, property), expected);
+    }
+}
+
+function testIsValidPropertyType() {
+    const data = [
+        [{}, 'invalid', true],
+        [{}, 0, false],
+        [{valid: 0}, 'valid', true],
+        [{null: 0}, null, false],
+        [[], 'invalid', false],
+        [[], 0, true],
+        [[0], 0, true],
+        [[0], null, false],
+        ['string', 0, false],
+        ['string', 'length', false],
+        ['string', null, false]
+    ];
+
+    for (const [object, property, expected] of data) {
+        assert.strictEqual(ObjectPropertyAccessor.isValidPropertyType(object, property), expected);
+    }
+}
+
+
+function main() {
+    testGetProperty1();
+    testGetProperty2();
+    testSetProperty1();
+    testSetProperty2();
+    testGetPathString1();
+    testGetPathString2();
+    testGetPathArray1();
+    testGetPathArray2();
+    testHasProperty();
+    testIsValidPropertyType();
+}
+
+
+if (require.main === module) { main(); }