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add cosmetic code fixes
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@slavaleleka
slavaleleka committed Sep 29, 2023
1 parent e3e0597 commit cfeba9c
Showing 1 changed file with 43 additions and 29 deletions.
72 changes: 43 additions & 29 deletions src/filters-downloader-creator.js
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Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,8 @@
const FiltersDownloaderCreator = (FileDownloadWrapper) => {
"use strict";

const CONDITION_DIRECTIVE_START = "!#if";
const CONDITION_IF_DIRECTIVE_START = "!#if";
const CONDITION_ELSE_DIRECTIVE_START = "!#else";
const CONDITION_DIRECTIVE_END = "!#endif";

const CONDITION_OPERATOR_NOT = "!";
Expand Down Expand Up @@ -75,19 +76,20 @@ const FiltersDownloaderCreator = (FileDownloadWrapper) => {
};

/**
* Finds end of condition block started with startIndex
* Finds end of condition block started with startIndex.
*
* @param rules
* @param startIndex
* @param {string[]} rules Array of all rules.
* @param {number} startIndex Index of the start of the condition block.
*
* @returns {number} Index of the end of the condition block.
*/
const findConditionEnd = (rules, startIndex) => {
const stack = [];
for (let j = startIndex; j < rules.length; j++) {
let internalRule = rules[j];

if (internalRule.startsWith(CONDITION_DIRECTIVE_START)) {
stack.push(CONDITION_DIRECTIVE_START);

if (internalRule.startsWith(CONDITION_IF_DIRECTIVE_START)) {
stack.push(CONDITION_IF_DIRECTIVE_START);
} else if (internalRule.startsWith(CONDITION_DIRECTIVE_END)) {
if (stack.length > 0) {
stack.pop();
Expand All @@ -101,10 +103,14 @@ const FiltersDownloaderCreator = (FileDownloadWrapper) => {
};

/**
* Resolves constant expression
* Resolves constant expression.
*
* @param expression
* @param definedProperties
* @param {string} expression
* @param {object} [definedProperties]
*
* @returns {boolean} True if expression is `'true'`
* or there is a property with the same name in `definedProperties` which is set to true,
* false otherwise.
*/
const resolveConditionConstant = (expression, definedProperties) => {
if (!expression) {
Expand All @@ -118,8 +124,11 @@ const FiltersDownloaderCreator = (FileDownloadWrapper) => {
/**
* Calculates conditional expression
*
* @param expression
* @param definedProperties
* @param {string} expression Conditional expression.
* @param {object} [definedProperties] Object with the defined properties
* where keys are platform names and values are booleans.
*
* @returns {boolean} Result of the expression
*/
const resolveExpression = (expression, definedProperties) => {
if (!expression) {
Expand Down Expand Up @@ -152,11 +161,11 @@ const FiltersDownloaderCreator = (FileDownloadWrapper) => {
const indexOfNotOperator = expression.indexOf(CONDITION_OPERATOR_NOT);

if (indexOfOrOperator !== -1) {
result = resolveExpression(expression.substring(0, indexOfOrOperator - 1), definedProperties) ||
resolveExpression(expression.substring(indexOfOrOperator + CONDITION_OPERATOR_OR.length, expression.length), definedProperties);
result = resolveExpression(expression.substring(0, indexOfOrOperator - 1), definedProperties)
|| resolveExpression(expression.substring(indexOfOrOperator + CONDITION_OPERATOR_OR.length, expression.length), definedProperties);
} else if (indexOfAndOperator !== -1) {
result = resolveExpression(expression.substring(0, indexOfAndOperator - 1), definedProperties) &&
resolveExpression(expression.substring(indexOfAndOperator + CONDITION_OPERATOR_AND.length, expression.length), definedProperties);
result = resolveExpression(expression.substring(0, indexOfAndOperator - 1), definedProperties)
&& resolveExpression(expression.substring(indexOfAndOperator + CONDITION_OPERATOR_AND.length, expression.length), definedProperties);
} else if (indexOfNotOperator === 0) {
result = !resolveExpression(expression.substring(CONDITION_OPERATOR_NOT.length), definedProperties);
} else {
Expand All @@ -173,16 +182,18 @@ const FiltersDownloaderCreator = (FileDownloadWrapper) => {
* @param definedProperties
*/
const resolveCondition = (directive, definedProperties) => {
const expression = directive.substring(CONDITION_DIRECTIVE_START.length).trim();
const expression = directive.substring(CONDITION_IF_DIRECTIVE_START.length).trim();

return resolveExpression(expression, definedProperties);
};

/**
* Resolves conditions directives
*
* @param rules
* @param definedProperties
* @param {string} rules Input array of rules.
* @param {object} [definedProperties] Object with the defined properties.
*
* @returns {string[]} Array of rules.
*/
const resolveConditions = (rules, definedProperties) => {
if (!definedProperties) {
Expand All @@ -192,17 +203,17 @@ const FiltersDownloaderCreator = (FileDownloadWrapper) => {
let result = [];

for (let i = 0; i < rules.length; i++) {
let rule = rules[i];
const rule = rules[i];

if (rule.indexOf(CONDITION_DIRECTIVE_START) === 0) {
if (rule.indexOf(CONDITION_IF_DIRECTIVE_START) === 0) {
let endLineIndex = findConditionEnd(rules, i + 1);
if (endLineIndex === -1) {
throw new Error('Invalid directives: Condition end not found: ' + rule);
}

let conditionValue = resolveCondition(rule, definedProperties);
if (conditionValue) {
let rulesUnderCondition = rules.slice(i + 1, endLineIndex);
const isConditionMatched = resolveCondition(rule, definedProperties);
if (isConditionMatched) {
const rulesUnderCondition = rules.slice(i + 1, endLineIndex);
// Resolve inner conditions in recursion
result = result.concat(resolveConditions(rulesUnderCondition, definedProperties));
}
Expand Down Expand Up @@ -287,12 +298,15 @@ const FiltersDownloaderCreator = (FileDownloadWrapper) => {
};

/**
* Compiles filter content
* Compiles filter content.
*
* @param {Array} rules Array of strings
* @param {?string} filterOrigin Filter file URL origin or null
* @param {?object} definedProperties An object with the defined properties. These properties might be used in pre-processor directives (`#if`, etc)
* @returns {Promise} A promise that returns {string} with rules when if resolved and {Error} if rejected.
* @param {Array} rules Array of strings.
* @param {string} [filterOrigin] Filter file URL origin or null.
* @param {object} [definedProperties] An object with the defined properties.
* These properties might be used in pre-processor directives (`#if`, etc).
*
* @returns {Promise} A promise that returns `string` with rules when if resolved
* and `Error` if rejected.
*/
const compile = (rules, filterOrigin, definedProperties) => {
try {
Expand Down

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