e97abeceb5
refs https://github.com/TryGhost/Team/issues/1386 - The current match handler supports normal (in)equality operators, but no numeric comparisons (<, >, <=, >=) - A use case for these new operators is to show the latest post in a separate way from other posts Includes unit tests to check the new behaviour. Run via `yarn test test/unit/frontend/helpers/match.test.js`
116 lines
3.2 KiB
JavaScript
116 lines
3.2 KiB
JavaScript
const {SafeString} = require('../services/rendering');
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const logging = require('@tryghost/logging');
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const tpl = require('@tryghost/tpl');
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const _ = require('lodash');
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const messages = {
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invalidAttribute: 'Invalid or no attribute given to match helper'
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};
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/**
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* This is identical to the built-in if helper, except inverse/fn calls are replaced with false/true
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* https://github.com/handlebars-lang/handlebars.js/blob/19bdace85a8d0bc5ed3a4dec4071cb08c8d003f2/lib/handlebars/helpers/if.js#L9-L20
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*/
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function isEmptyValue(value) {
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if (!value && value !== 0) {
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return true;
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} else if (Array.isArray(value) && value.length === 0) {
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return true;
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} else {
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return false;
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}
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}
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const handleConditional = (conditional, options) => {
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if (_.isFunction(conditional)) {
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conditional = conditional.call(this);
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}
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// Default behavior is to render the positive path if the value is truthy and not empty.
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// The `includeZero` option may be set to treat the condtional as purely not empty based on the
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// behavior of isEmpty. Effectively this determines if 0 is handled by the positive path or negative.
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if ((!options.hash.includeZero && !conditional) || isEmptyValue(conditional)) {
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return false;
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} else {
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return true;
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}
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};
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const handleMatch = (data, operator, value) => {
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let result;
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switch (operator) {
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case '!=':
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result = data !== value;
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break;
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case '<':
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result = data < value;
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break;
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case '>':
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result = data > value;
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break;
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case '>=':
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result = data >= value;
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break;
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case '<=':
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result = data <= value;
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break;
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default:
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result = data === value;
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}
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return result;
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};
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module.exports = function match(...attrs) {
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// options = options || {};
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// options.hash = options.hash || {};
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// options.data = options.data || {};
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const options = attrs.pop();
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const isBlock = _.has(options, 'fn');
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let result;
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if (_.isEmpty(attrs)) {
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logging.warn(tpl(messages.invalidAttribute));
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return;
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}
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// If any of the attributes are safe strings, change them back to their original value
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attrs = attrs.map((attr) => {
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if (attr instanceof SafeString) {
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return attr.string;
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}
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return attr;
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});
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if (attrs.length === 1) {
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// CASE: single attribute, treat it as simple true/false (like the if helper)
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result = handleConditional(attrs[0], options);
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} else if (attrs.length === 2) {
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// CASE: two attributes, assume the operator is "="
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result = handleMatch(attrs[0], '=', attrs[1]);
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} else if (attrs.length === 3) {
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// CASE: three attributes, handle the match exactly
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result = handleMatch(attrs[0], attrs[1], attrs[2]);
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} else {
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logging.warn(tpl(messages.invalidAttribute));
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return;
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}
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// If we're in block mode, return the outcome from the fn/inverse functions
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if (isBlock) {
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if (result) {
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return options.fn(this);
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}
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return options.inverse(this);
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}
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// Else return the result as a SafeString Eg.{string: false} || {string: true}
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return new SafeString(result);
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};
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