Joey Perrott d1ea1f4c7f build: update license headers to reference Google LLC ()
Update the license headers throughout the repository to reference Google LLC
rather than Google Inc, for the required license headers.

PR Close 
2020-05-26 14:26:58 -04:00

100 lines
3.9 KiB
TypeScript

/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {IMinimatch, Minimatch} from 'minimatch';
/** Map that holds patterns and their corresponding Minimatch globs. */
const patternCache = new Map<string, IMinimatch>();
/**
* Context that is provided to conditions. Conditions can use various helpers
* that PullApprove provides. We try to mock them here. Consult the official
* docs for more details: https://docs.pullapprove.com/config/conditions.
*/
const conditionContext = {
'len': (value: any[]) => value.length,
'contains_any_globs': (files: PullApproveArray, patterns: string[]) => {
// Note: Do not always create globs for the same pattern again. This method
// could be called for each source file. Creating glob's is expensive.
return files.some(f => patterns.some(pattern => getOrCreateGlob(pattern).match(f)));
}
};
/**
* Converts a given condition to a function that accepts a set of files. The returned
* function can be called to check if the set of files matches the condition.
*/
export function convertConditionToFunction(expr: string): (files: string[]) => boolean {
// Creates a dynamic function with the specified expression. The first parameter will
// be `files` as that corresponds to the supported `files` variable that can be accessed
// in PullApprove condition expressions. The followed parameters correspond to other
// context variables provided by PullApprove for conditions.
const evaluateFn = new Function('files', ...Object.keys(conditionContext), `
return (${transformExpressionToJs(expr)});
`);
// Create a function that calls the dynamically constructed function which mimics
// the condition expression that is usually evaluated with Python in PullApprove.
return files => {
const result = evaluateFn(new PullApproveArray(...files), ...Object.values(conditionContext));
// If an array is returned, we consider the condition as active if the array is not
// empty. This matches PullApprove's condition evaluation that is based on Python.
if (Array.isArray(result)) {
return result.length !== 0;
}
return !!result;
};
}
/**
* Transforms a condition expression from PullApprove that is based on python
* so that it can be run inside JavaScript. Current transformations:
* 1. `not <..>` -> `!<..>`
*/
function transformExpressionToJs(expression: string): string {
return expression.replace(/not\s+/g, '!');
}
/**
* Superset of a native array. The superset provides methods which mimic the
* list data structure used in PullApprove for files in conditions.
*/
class PullApproveArray extends Array<string> {
constructor(...elements: string[]) {
super(...elements);
// Set the prototype explicitly because in ES5, the prototype is accidentally
// lost due to a limitation in down-leveling.
// https://github.com/Microsoft/TypeScript/wiki/FAQ#why-doesnt-extending-built-ins-like-error-array-and-map-work.
Object.setPrototypeOf(this, PullApproveArray.prototype);
}
/** Returns a new array which only includes files that match the given pattern. */
include(pattern: string): PullApproveArray {
return new PullApproveArray(...this.filter(s => getOrCreateGlob(pattern).match(s)));
}
/** Returns a new array which only includes files that did not match the given pattern. */
exclude(pattern: string): PullApproveArray {
return new PullApproveArray(...this.filter(s => !getOrCreateGlob(pattern).match(s)));
}
}
/**
* Gets a glob for the given pattern. The cached glob will be returned
* if available. Otherwise a new glob will be created and cached.
*/
function getOrCreateGlob(pattern: string) {
if (patternCache.has(pattern)) {
return patternCache.get(pattern)!;
}
const glob = new Minimatch(pattern, {dot: true});
patternCache.set(pattern, glob);
return glob;
}