Current File : /var/www/html/node_modules/eslint/lib/cli-engine/lint-result-cache.js
/**
* @fileoverview Utility for caching lint results.
* @author Kevin Partington
*/
"use strict";
//-----------------------------------------------------------------------------
// Requirements
//-----------------------------------------------------------------------------
const assert = require("assert");
const fs = require("fs");
const fileEntryCache = require("file-entry-cache");
const stringify = require("json-stable-stringify-without-jsonify");
const pkg = require("../../package.json");
const hash = require("./hash");
const debug = require("debug")("eslint:lint-result-cache");
//-----------------------------------------------------------------------------
// Helpers
//-----------------------------------------------------------------------------
const configHashCache = new WeakMap();
const nodeVersion = process && process.version;
const validCacheStrategies = ["metadata", "content"];
const invalidCacheStrategyErrorMessage = `Cache strategy must be one of: ${validCacheStrategies
.map(strategy => `"${strategy}"`)
.join(", ")}`;
/**
* Tests whether a provided cacheStrategy is valid
* @param {string} cacheStrategy The cache strategy to use
* @returns {boolean} true if `cacheStrategy` is one of `validCacheStrategies`; false otherwise
*/
function isValidCacheStrategy(cacheStrategy) {
return (
validCacheStrategies.indexOf(cacheStrategy) !== -1
);
}
/**
* Calculates the hash of the config
* @param {ConfigArray} config The config.
* @returns {string} The hash of the config
*/
function hashOfConfigFor(config) {
if (!configHashCache.has(config)) {
configHashCache.set(config, hash(`${pkg.version}_${nodeVersion}_${stringify(config)}`));
}
return configHashCache.get(config);
}
//-----------------------------------------------------------------------------
// Public Interface
//-----------------------------------------------------------------------------
/**
* Lint result cache. This wraps around the file-entry-cache module,
* transparently removing properties that are difficult or expensive to
* serialize and adding them back in on retrieval.
*/
class LintResultCache {
/**
* Creates a new LintResultCache instance.
* @param {string} cacheFileLocation The cache file location.
* @param {"metadata" | "content"} cacheStrategy The cache strategy to use.
*/
constructor(cacheFileLocation, cacheStrategy) {
assert(cacheFileLocation, "Cache file location is required");
assert(cacheStrategy, "Cache strategy is required");
assert(
isValidCacheStrategy(cacheStrategy),
invalidCacheStrategyErrorMessage
);
debug(`Caching results to ${cacheFileLocation}`);
const useChecksum = cacheStrategy === "content";
debug(
`Using "${cacheStrategy}" strategy to detect changes`
);
this.fileEntryCache = fileEntryCache.create(
cacheFileLocation,
void 0,
useChecksum
);
this.cacheFileLocation = cacheFileLocation;
}
/**
* Retrieve cached lint results for a given file path, if present in the
* cache. If the file is present and has not been changed, rebuild any
* missing result information.
* @param {string} filePath The file for which to retrieve lint results.
* @param {ConfigArray} config The config of the file.
* @returns {Object|null} The rebuilt lint results, or null if the file is
* changed or not in the filesystem.
*/
getCachedLintResults(filePath, config) {
/*
* Cached lint results are valid if and only if:
* 1. The file is present in the filesystem
* 2. The file has not changed since the time it was previously linted
* 3. The ESLint configuration has not changed since the time the file
* was previously linted
* If any of these are not true, we will not reuse the lint results.
*/
const fileDescriptor = this.fileEntryCache.getFileDescriptor(filePath);
const hashOfConfig = hashOfConfigFor(config);
const changed =
fileDescriptor.changed ||
fileDescriptor.meta.hashOfConfig !== hashOfConfig;
if (fileDescriptor.notFound) {
debug(`File not found on the file system: ${filePath}`);
return null;
}
if (changed) {
debug(`Cache entry not found or no longer valid: ${filePath}`);
return null;
}
// If source is present but null, need to reread the file from the filesystem.
if (
fileDescriptor.meta.results &&
fileDescriptor.meta.results.source === null
) {
debug(`Rereading cached result source from filesystem: ${filePath}`);
fileDescriptor.meta.results.source = fs.readFileSync(filePath, "utf-8");
}
return fileDescriptor.meta.results;
}
/**
* Set the cached lint results for a given file path, after removing any
* information that will be both unnecessary and difficult to serialize.
* Avoids caching results with an "output" property (meaning fixes were
* applied), to prevent potentially incorrect results if fixes are not
* written to disk.
* @param {string} filePath The file for which to set lint results.
* @param {ConfigArray} config The config of the file.
* @param {Object} result The lint result to be set for the file.
* @returns {void}
*/
setCachedLintResults(filePath, config, result) {
if (result && Object.prototype.hasOwnProperty.call(result, "output")) {
return;
}
const fileDescriptor = this.fileEntryCache.getFileDescriptor(filePath);
if (fileDescriptor && !fileDescriptor.notFound) {
debug(`Updating cached result: ${filePath}`);
// Serialize the result, except that we want to remove the file source if present.
const resultToSerialize = Object.assign({}, result);
/*
* Set result.source to null.
* In `getCachedLintResults`, if source is explicitly null, we will
* read the file from the filesystem to set the value again.
*/
if (Object.prototype.hasOwnProperty.call(resultToSerialize, "source")) {
resultToSerialize.source = null;
}
fileDescriptor.meta.results = resultToSerialize;
fileDescriptor.meta.hashOfConfig = hashOfConfigFor(config);
}
}
/**
* Persists the in-memory cache to disk.
* @returns {void}
*/
reconcile() {
debug(`Persisting cached results: ${this.cacheFileLocation}`);
this.fileEntryCache.reconcile();
}
}
module.exports = LintResultCache;
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