fix: remove @types/eslint dependency as eslint is optional

✅ Closes: #379

Author: piotr-oles

package.json

@@ -85,7 +85,6 @@
  "devDependencies": {
  "@commitlint/config-conventional": "^7.5.0",
  "@types/babel-code-frame": "^6.20.1",
- "@types/eslint": "^4.16.6",
  "@types/jest": "^24.0.11",
  "@types/lodash": "^4.14.134",
  "@types/micromatch": "^3.1.0",

src/ApiIncrementalChecker.ts

@@ -1,5 +1,3 @@
-import * as eslint from 'eslint'; // Imported for types alone
-
 import {
  IncrementalCheckerInterface,
  IncrementalCheckerParams
@@ -11,11 +9,12 @@ import {
  createIssuesFromTsDiagnostics,
  createIssuesFromEsLintReports
 } from './issue';
+import { LintReport } from './types/eslint';
 
 export class ApiIncrementalChecker implements IncrementalCheckerInterface {
  protected readonly tsIncrementalCompiler: CompilerHost;
 
- private currentEsLintErrors = new Map<string, eslint.CLIEngine.LintReport>();
+ private currentEsLintErrors = new Map<string, LintReport>();
  private lastUpdatedFiles: string[] = [];
  private lastRemovedFiles: string[] = [];
 

src/FilesRegister.ts

@@ -1,10 +1,10 @@
 import * as ts from 'typescript'; // import for types alone
-import * as eslint from 'eslint'; // import for types alone
+import { LintReport } from './types/eslint';
 
 export interface DataShape {
  source?: ts.SourceFile;
  linted: boolean;
- eslints: eslint.CLIEngine.LintReport[];
+ eslints: LintReport[];
 }
 
 export class FilesRegister {

src/IncrementalChecker.ts

@@ -1,7 +1,6 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import * as ts from 'typescript'; // Imported for types alone; actual requires take place in methods below
-import * as eslint from 'eslint';
 
 import { FilesRegister } from './FilesRegister';
 import { CancellationToken } from './CancellationToken';
@@ -22,6 +21,7 @@ import {
  createIssuesFromEsLintReports,
  createIssuesFromTsDiagnostics
 } from './issue';
+import { LintReport } from './types/eslint';
 
 export class IncrementalChecker implements IncrementalCheckerInterface {
  private files = new FilesRegister(() => ({
@@ -261,7 +261,7 @@ export class IncrementalChecker implements IncrementalCheckerInterface {
  !IncrementalChecker.isFileExcluded(filePath)
  );
 
- const currentEsLintErrors = new Map<string, eslint.CLIEngine.LintReport>();
+ const currentEsLintErrors = new Map<string, LintReport>();
  filesToLint.forEach(fileName => {
  cancellationToken.throwIfCancellationRequested();
 
@@ -289,7 +289,7 @@ export class IncrementalChecker implements IncrementalCheckerInterface {
 
  const reports = this.files
  .keys()
- .reduce<eslint.CLIEngine.LintReport[]>(
+ .reduce<LintReport[]>(
  (innerLints, filePath) =>
  innerLints.concat(this.files.getData(filePath).eslints),
  []

src/createEslinter.ts

@@ -1,16 +1,16 @@
-import * as eslint from 'eslint'; // import for types alone
 import * as path from 'path';
 
+import { LintReport } from './types/eslint';
 import { throwIfIsInvalidSourceFileError } from './FsHelper';
 
 export function createEslinter(eslintOptions: object) {
  // eslint-disable-next-line @typescript-eslint/no-var-requires
- const { CLIEngine }: typeof eslint = require('eslint');
+ const { CLIEngine } = require('eslint');
 
  // See https://eslint.org/docs/1.0.0/developer-guide/nodejs-api#cliengine
  const eslinter = new CLIEngine(eslintOptions);
 
- function getReport(filepath: string) {
+ function getReport(filepath: string): LintReport | undefined {
  try {
  if (
  eslinter.isPathIgnored(filepath) ||

src/issue/eslint/EsLintIssueFactory.ts

@@ -1,8 +1,8 @@
-import * as eslint from 'eslint';
 import { FileAwareEsLintMessage } from './FileAwareEsLintMessage';
 import { deduplicateAndSortIssues, Issue } from '../Issue';
 import { IssueOrigin } from '../IssueOrigin';
 import { IssueSeverity } from '../IssueSeverity';
+import { LintReport, LintResult } from '../../types/eslint';
 
 function createIssueFromEsLintMessage(message: FileAwareEsLintMessage): Issue {
  return {
@@ -18,7 +18,7 @@ function createIssueFromEsLintMessage(message: FileAwareEsLintMessage): Issue {
 }
 
 function createFileAwareEsLintMessagesFromEsLintResult(
- result: eslint.CLIEngine.LintResult
+ result: LintResult
 ): FileAwareEsLintMessage[] {
  return result.messages.map(message => ({
  ...message,
@@ -27,7 +27,7 @@ function createFileAwareEsLintMessagesFromEsLintResult(
 }
 
 function createFileAwareEsLintMessagesFromEsLintReport(
- report: eslint.CLIEngine.LintReport
+ report: LintReport
 ): FileAwareEsLintMessage[] {
  return report.results.reduce<FileAwareEsLintMessage[]>(
  (messages, result) => [
@@ -39,7 +39,7 @@ function createFileAwareEsLintMessagesFromEsLintReport(
 }
 
 function createFileAwareEsLintMessagesFromEsLintReports(
- reports: eslint.CLIEngine.LintReport[]
+ reports: LintReport[]
 ): FileAwareEsLintMessage[] {
  return reports.reduce<FileAwareEsLintMessage[]>(
  (messages, report) => [
@@ -56,9 +56,7 @@ function createIssuesFromEsLintMessages(
  return deduplicateAndSortIssues(messages.map(createIssueFromEsLintMessage));
 }
 
-function createIssuesFromEsLintReports(
- reports: eslint.CLIEngine.LintReport[]
-): Issue[] {
+function createIssuesFromEsLintReports(reports: LintReport[]): Issue[] {
  return createIssuesFromEsLintMessages(
  createFileAwareEsLintMessagesFromEsLintReports(reports)
  );

src/issue/eslint/FileAwareEsLintMessage.ts

@@ -1,10 +1,10 @@
-import * as eslint from 'eslint';
+import { LintMessage } from '../../types/eslint';
 
 /**
  * We need to define custom interface because of eslint architecture which
  * groups lint messages per file
  */
-interface FileAwareEsLintMessage extends eslint.Linter.LintMessage {
+interface FileAwareEsLintMessage extends LintMessage {
  filePath?: string;
 }
 

src/types/eslint.ts

@@ -0,0 +1,36 @@
+// copy eslint types as installation of eslint package is optional
+export interface LintMessage {
+ column: number;
+ line: number;
+ endColumn?: number;
+ endLine?: number;
+ ruleId: string | null;
+ message: string;
+ nodeType: string;
+ fatal?: true;
+ severity: 0 | 1 | 2;
+ fix?: {
+ range: [number, number];
+ text: string;
+ };
+ source: string | null;
+}
+
+export interface LintResult {
+ filePath: string;
+ messages: LintMessage[];
+ errorCount: number;
+ warningCount: number;
+ fixableErrorCount: number;
+ fixableWarningCount: number;
+ output?: string;
+ source?: string;
+}
+
+export interface LintReport {
+ results: LintResult[];
+ errorCount: number;
+ warningCount: number;
+ fixableErrorCount: number;
+ fixableWarningCount: number;
+}

test/unit/issue/eslint/EsLintIssueFactory.spec.ts

@@ -1,11 +1,11 @@
 import { createIssuesFromEsLintReports } from '../../../../lib/issue';
-import * as eslint from 'eslint';
+import {
+ LintMessage,
+ LintReport,
+ LintResult
+} from '../../../../lib/types/eslint';
 
 describe('[UNIT] issue/eslint/EsLintIssueFactory', () => {
- type LintMessage = eslint.Linter.LintMessage;
- type LintResult = eslint.CLIEngine.LintResult;
- type LintReport = eslint.CLIEngine.LintReport;
-
  const ES_LINT_MESSAGE_ERROR: LintMessage = {
  column: 0,
  line: 13,

yarn.lock

@@ -490,19 +490,6 @@
  resolved "https://registry.yarnpkg.com/@types/eslint-visitor-keys/-/eslint-visitor-keys-1.0.0.tgz#1ee30d79544ca84d68d4b3cdb0af4f205663dd2d"
  integrity sha512-OCutwjDZ4aFS6PB1UZ988C4YgwlBHJd6wCeQqaLdmadZ/7e+w79+hbMUFC1QXDNCmdyoRfAFdm0RypzwR+Qpag==
 
-"@types/eslint@^4.16.6":
- version "4.16.6"
- resolved "https://registry.yarnpkg.com/@types/eslint/-/eslint-4.16.6.tgz#96d4ecddbea618ab0b55eaf0dffedf387129b06c"
- integrity sha512-GL7tGJig55FeclpOytU7nCCqtR143jBoC7AUdH0DO9xBSIFiNNUFCY/S3KNWsHeQJuU3hjw/OC1+kRTFNXqUZQ==
- dependencies:
- "@types/estree" "*"
- "@types/json-schema" "*"
-
-"@types/estree@*":
- version "0.0.39"
- resolved "https://registry.yarnpkg.com/@types/estree/-/estree-0.0.39.tgz#e177e699ee1b8c22d23174caaa7422644389509f"
- integrity sha512-EYNwp3bU+98cpU4lAWYYL7Zz+2gryWH1qbdDTidVd6hkiR6weksdbMadyXKXNPEkQFhXM+hVO9ZygomHXp+AIw==
-
 "@types/events@*":
  version "1.2.0"
  resolved "https://registry.yarnpkg.com/@types/events/-/events-1.2.0.tgz#81a6731ce4df43619e5c8c945383b3e62a89ea86"
@@ -533,7 +520,7 @@
  dependencies:
  "@types/jest-diff" "*"
 
-"@types/json-schema@*", "@types/json-schema@^7.0.3":
+"@types/json-schema@^7.0.3":
  version "7.0.3"
  resolved "https://registry.yarnpkg.com/@types/json-schema/-/json-schema-7.0.3.tgz#bdfd69d61e464dcc81b25159c270d75a73c1a636"
  integrity sha512-Il2DtDVRGDcqjDtE+rF8iqg1CArehSK84HZJCT7AMITlyXRBpuPhqGLDQMowraqqu1coEaimg4ZOqggt6L6L+A==