odin-javascript-exercises/node_modules/eslint/lib/report-translator.js
2017-12-15 12:56:14 -06:00

274 lines
9 KiB
JavaScript

/**
* @fileoverview A helper that translates context.report() calls from the rule API into generic problem objects
* @author Teddy Katz
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const assert = require("assert");
const ruleFixer = require("./util/rule-fixer");
//------------------------------------------------------------------------------
// Typedefs
//------------------------------------------------------------------------------
/**
* An error message description
* @typedef {Object} MessageDescriptor
* @property {ASTNode} [node] The reported node
* @property {Location} loc The location of the problem.
* @property {string} message The problem message.
* @property {Object} [data] Optional data to use to fill in placeholders in the
* message.
* @property {Function} [fix] The function to call that creates a fix command.
*/
//------------------------------------------------------------------------------
// Module Definition
//------------------------------------------------------------------------------
/**
* Translates a multi-argument context.report() call into a single object argument call
* @param {...*} arguments A list of arguments passed to `context.report`
* @returns {MessageDescriptor} A normalized object containing report information
*/
function normalizeMultiArgReportCall() {
// If there is one argument, it is considered to be a new-style call already.
if (arguments.length === 1) {
return arguments[0];
}
// If the second argument is a string, the arguments are interpreted as [node, message, data, fix].
if (typeof arguments[1] === "string") {
return {
node: arguments[0],
message: arguments[1],
data: arguments[2],
fix: arguments[3]
};
}
// Otherwise, the arguments are interpreted as [node, loc, message, data, fix].
return {
node: arguments[0],
loc: arguments[1],
message: arguments[2],
data: arguments[3],
fix: arguments[4]
};
}
/**
* Asserts that either a loc or a node was provided, and the node is valid if it was provided.
* @param {MessageDescriptor} descriptor A descriptor to validate
* @returns {void}
* @throws AssertionError if neither a node nor a loc was provided, or if the node is not an object
*/
function assertValidNodeInfo(descriptor) {
if (descriptor.node) {
assert(typeof descriptor.node === "object", "Node must be an object");
} else {
assert(descriptor.loc, "Node must be provided when reporting error if location is not provided");
}
}
/**
* Normalizes a MessageDescriptor to always have a `loc` with `start` and `end` properties
* @param {MessageDescriptor} descriptor A descriptor for the report from a rule.
* @returns {{start: Location, end: (Location|null)}} An updated location that infers the `start` and `end` properties
* from the `node` of the original descriptor, or infers the `start` from the `loc` of the original descriptor.
*/
function normalizeReportLoc(descriptor) {
if (descriptor.loc) {
if (descriptor.loc.start) {
return descriptor.loc;
}
return { start: descriptor.loc, end: null };
}
return descriptor.node.loc;
}
/**
* Interpolates data placeholders in report messages
* @param {MessageDescriptor} descriptor The report message descriptor.
* @returns {string} The interpolated message for the descriptor
*/
function normalizeMessagePlaceholders(descriptor) {
if (!descriptor.data) {
return descriptor.message;
}
return descriptor.message.replace(/\{\{\s*([^{}]+?)\s*\}\}/g, (fullMatch, term) => {
if (term in descriptor.data) {
return descriptor.data[term];
}
return fullMatch;
});
}
/**
* Compares items in a fixes array by range.
* @param {Fix} a The first message.
* @param {Fix} b The second message.
* @returns {int} -1 if a comes before b, 1 if a comes after b, 0 if equal.
* @private
*/
function compareFixesByRange(a, b) {
return a.range[0] - b.range[0] || a.range[1] - b.range[1];
}
/**
* Merges the given fixes array into one.
* @param {Fix[]} fixes The fixes to merge.
* @param {SourceCode} sourceCode The source code object to get the text between fixes.
* @returns {{text: string, range: [number, number]}} The merged fixes
*/
function mergeFixes(fixes, sourceCode) {
if (fixes.length === 0) {
return null;
}
if (fixes.length === 1) {
return fixes[0];
}
fixes.sort(compareFixesByRange);
const originalText = sourceCode.text;
const start = fixes[0].range[0];
const end = fixes[fixes.length - 1].range[1];
let text = "";
let lastPos = Number.MIN_SAFE_INTEGER;
for (const fix of fixes) {
assert(fix.range[0] >= lastPos, "Fix objects must not be overlapped in a report.");
if (fix.range[0] >= 0) {
text += originalText.slice(Math.max(0, start, lastPos), fix.range[0]);
}
text += fix.text;
lastPos = fix.range[1];
}
text += originalText.slice(Math.max(0, start, lastPos), end);
return { range: [start, end], text };
}
/**
* Gets one fix object from the given descriptor.
* If the descriptor retrieves multiple fixes, this merges those to one.
* @param {MessageDescriptor} descriptor The report descriptor.
* @param {SourceCode} sourceCode The source code object to get text between fixes.
* @returns {({text: string, range: [number, number]}|null)} The fix for the descriptor
*/
function normalizeFixes(descriptor, sourceCode) {
if (typeof descriptor.fix !== "function") {
return null;
}
// @type {null | Fix | Fix[] | IterableIterator<Fix>}
const fix = descriptor.fix(ruleFixer);
// Merge to one.
if (fix && Symbol.iterator in fix) {
return mergeFixes(Array.from(fix), sourceCode);
}
return fix;
}
/**
* Creates information about the report from a descriptor
* @param {{
* ruleId: string,
* severity: (0|1|2),
* node: (ASTNode|null),
* message: string,
* loc: {start: SourceLocation, end: (SourceLocation|null)},
* fix: ({text: string, range: [number, number]}|null),
* sourceLines: string[]
* }} options Information about the problem
* @returns {function(...args): {
* ruleId: string,
* severity: (0|1|2),
* message: string,
* line: number,
* column: number,
* endLine: (number|undefined),
* endColumn: (number|undefined),
* nodeType: (string|null),
* source: string,
* fix: ({text: string, range: [number, number]}|null)
* }} Information about the report
*/
function createProblem(options) {
const problem = {
ruleId: options.ruleId,
severity: options.severity,
message: options.message,
line: options.loc.start.line,
column: options.loc.start.column + 1,
nodeType: options.node && options.node.type || null,
source: options.sourceLines[options.loc.start.line - 1] || ""
};
if (options.loc.end) {
problem.endLine = options.loc.end.line;
problem.endColumn = options.loc.end.column + 1;
}
if (options.fix) {
problem.fix = options.fix;
}
return problem;
}
/**
* Returns a function that converts the arguments of a `context.report` call from a rule into a reported
* problem for the Node.js API.
* @param {{ruleId: string, severity: number, sourceCode: SourceCode}} metadata Metadata for the reported problem
* @param {SourceCode} sourceCode The `SourceCode` instance for the text being linted
* @returns {function(...args): {
* ruleId: string,
* severity: (0|1|2),
* message: string,
* line: number,
* column: number,
* endLine: (number|undefined),
* endColumn: (number|undefined),
* nodeType: (string|null),
* source: string,
* fix: ({text: string, range: [number, number]}|null)
* }}
* Information about the report
*/
module.exports = function createReportTranslator(metadata) {
/*
* `createReportTranslator` gets called once per enabled rule per file. It needs to be very performant.
* The report translator itself (i.e. the function that `createReportTranslator` returns) gets
* called every time a rule reports a problem, which happens much less frequently (usually, the vast
* majority of rules don't report any problems for a given file).
*/
return function() {
const descriptor = normalizeMultiArgReportCall.apply(null, arguments);
assertValidNodeInfo(descriptor);
return createProblem({
ruleId: metadata.ruleId,
severity: metadata.severity,
node: descriptor.node,
message: normalizeMessagePlaceholders(descriptor),
loc: normalizeReportLoc(descriptor),
fix: normalizeFixes(descriptor, metadata.sourceCode),
sourceLines: metadata.sourceCode.lines
});
};
};