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/**

* Copyright 2015 The AMP HTML Authors. All Rights Reserved.

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS-IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*/

/**

* @param {string} name Attribute name with dashes

* @return {string} Dashes removed and character after to upper case.

* visibleForTesting

*/

export function dashToCamelCase(name) {

return name.replace(/-([a-z])/g, function(_all, character) {

return character.toUpperCase();

});

}

/**

* Polyfill for String.prototype. endsWith.

* @param {string} string

* @param {string} suffix

* @return {boolean}

*/

export function endsWith(string, suffix) {

if (suffix.length > string.length) {

return false;

}

const index = string.length - suffix.length;

return string.indexOf(suffix, index) == index;

}

/**

* Polyfill for String.prototype. startsWith.

* @param {string} string

* @param {string} prefix

* @return {boolean}

*/

export function startsWith(string, prefix) {

if (prefix.length > string.length) {

return false;

}

return string.lastIndexOf(prefix, 0) == 0;

}

/**

* Expands placeholders in a given template string with values.

*

* Placeholders use ${key-name} syntax and are replaced with the value

* returned from the given getter function.

*

* @param {string} template The template string to expand.

* @param {!function(string):*} getter Function used to retrieve a value for a

* placeholder. Returns values will be coerced into strings.

* @param {number=} opt_maxIterations Number of times to expand the template.

* Defaults to 1, but should be set to a larger value your placeholder tokens

* can be expanded to other placeholder tokens. Take caution with large values

* as recursively expanding a string can be exponentially expensive.

*/

export function expandTemplate(template, getter, opt_maxIterations) {

const maxIterations = opt_maxIterations || 1;

for (let i = 0; i < maxIterations; i++) {

let matches = 0;

template = template.replace(/\${([^}]*)}/g, (_a, b) => {

matches++;

return getter(b);

});

if (!matches) {

break;

}

}

return template;

}