Fix all lint errors, adding a lint CI step (#175)

Test Plan:
Run `yarn lint` and `yarn travis` and observe success. Add something
that triggers a lint warning, like `const zzz = 3;`; re-run and observe
failures.

wchargin-branch: lint

.eslintrc.js

@@ -0,0 +1,14 @@
+module.exports = {
+  extends: "react-app",
+  rules: {
+    "no-unused-vars": [
+      "warn",
+      {
+        argsIgnorePattern: "^_$|^_unused_",
+        varsIgnorePattern: "^_$|^_unused_",
+        caughtErrorsIgnorePattern: "^_$|^_unused_",
+      },
+    ],
+    "no-use-before-define": ["off"],
+  },
+};

config/env.js

@@ -1,5 +1,3 @@
-"use strict";
-
 const fs = require("fs");
 const path = require("path");
 const paths = require("./paths");

config/jest/cssTransform.js

@@ -1,5 +1,3 @@
-"use strict";
-
 // This is a custom Jest transformer turning style imports into empty objects.
 // http://facebook.github.io/jest/docs/en/webpack.html
 

config/jest/fileTransform.js

@@ -1,5 +1,3 @@
-"use strict";
-
 const path = require("path");
 
 // This is a custom Jest transformer turning file imports into filenames.

config/paths.js

@@ -1,5 +1,3 @@
-"use strict";
-
 const path = require("path");
 const fs = require("fs");
 const url = require("url");

config/polyfills.js

@@ -1,5 +1,3 @@
-"use strict";
-
 if (typeof Promise === "undefined") {
   // Rejection tracking prevents a common issue where React gets into an
   // inconsistent state due to an error, but it gets swallowed by a Promise,

config/webpack.config.backend.js

@@ -1,6 +1,3 @@
-"use strict";
-
-const path = require("path");
 const webpack = require("webpack");
 const eslintFormatter = require("react-dev-utils/eslintFormatter");
 const ModuleScopePlugin = require("react-dev-utils/ModuleScopePlugin");
@@ -68,6 +65,7 @@ module.exports = {
         ],
       },
     ],
+    exprContextCritical: false,
   },
   plugins: [
     new webpack.DefinePlugin({

config/webpack.config.dev.js

@@ -1,5 +1,3 @@
-"use strict";
-
 const autoprefixer = require("autoprefixer");
 const path = require("path");
 const webpack = require("webpack");

config/webpack.config.prod.js

@@ -1,5 +1,3 @@
-"use strict";
-
 const autoprefixer = require("autoprefixer");
 const path = require("path");
 const webpack = require("webpack");

config/webpackDevServer.config.js

@@ -1,5 +1,3 @@
-"use strict";
-
 const errorOverlayMiddleware = require("react-dev-utils/errorOverlayMiddleware");
 const noopServiceWorkerMiddleware = require("react-dev-utils/noopServiceWorkerMiddleware");
 const ignoredFiles = require("react-dev-utils/ignoredFiles");

package.json

@@ -62,7 +62,8 @@
     "backend": "node scripts/backend.js",
     "test": "node scripts/test.js --env=jsdom",
     "flow": "flow",
-    "travis": "npm run check-pretty && npm run flow && CI=true npm run test"
+    "lint": "eslint src config --max-warnings 0",
+    "travis": "npm run check-pretty && npm run lint && npm run flow && CI=true npm run test"
   },
   "license": "MIT",
   "lint-staged": {
@@ -110,9 +111,6 @@
       "react-app"
     ]
   },
-  "eslintConfig": {
-    "extends": "react-app"
-  },
   "devDependencies": {
     "babel-plugin-flow-react-proptypes": "^18.0.0",
     "enzyme": "^3.3.0",

src/core/address.test.js

@@ -55,7 +55,7 @@ describe("address", () => {
       const actual = makeMap().getAll();
       const expected = [mansion(), mattressStore()];
       const sort = (xs) => sortBy(xs, (x) => stringify(x.address));
-      expect(sort(actual)).toEqual(sort(actual));
+      expect(sort(actual)).toEqual(sort(expected));
     });
 
     it("removes objects by key", () => {

src/core/graph.test.js

@@ -305,7 +305,7 @@ describe("graph", () => {
           demoData.crabLoopEdge()
         );
         const crabNeighbors = g.neighborhood(demoData.crabNode().address);
-        const crabLoops = crabNeighbors.filter(({edge, neighborAddress}) =>
+        const crabLoops = crabNeighbors.filter(({edge}) =>
           deepEqual(edge, demoData.crabLoopEdge())
         );
         expect(crabLoops).toHaveLength(1);
@@ -470,9 +470,7 @@ describe("graph", () => {
         describe("neighborhood", () => {
           const eg = new ExampleGraph();
           const edges = (opts) =>
-            eg.graph
-              .neighborhood(eg.root, opts)
-              .map(({edge, neighborAddress}) => edge);
+            eg.graph.neighborhood(eg.root, opts).map(({edge}) => edge);
           const allEdges = [
             eg.inEdges.a1,
             eg.inEdges.a2,
@@ -1138,7 +1136,7 @@ describe("graph", () => {
         expect(g1.equals(demoData.advancedMealGraph())).toBe(true);
       });
 
-      function itAllowsUpcastingPayloadTypes(
+      function _unused_itAllowsUpcastingPayloadTypes(
         g: Graph<{x: string, y: number}, boolean>
       ): Graph<{x: string}, ?boolean> {
         return g.copy();

src/graphql/queries.js

@@ -290,7 +290,7 @@ export const stringify = {
   },
 
   parameter(parameter: Parameter, ls: LayoutStrategy): string {
-    return ls.atom(`\$${parameter.name}: ${parameter.type}`);
+    return ls.atom(`$${parameter.name}: ${parameter.type}`);
   },
 
   fragmentDefinition(fragment: FragmentDefinition, ls: LayoutStrategy): string {
@@ -388,7 +388,7 @@ export const stringify = {
   },
 
   variableValue(value: VariableValue, ls: LayoutStrategy): string {
-    return ls.atom(`\$${value.data}`);
+    return ls.atom(`$${value.data}`);
   },
 
   literalValue(value: LiteralValue, ls: LayoutStrategy): string {

src/plugins/artifact/editor/ArtifactGraphEditor.js

@@ -105,9 +105,9 @@ export class ArtifactGraphEditor extends React.Component<Props, State> {
           value={this.state.artifactInProgressName}
           onChange={(e) => {
             const value = e.target.value;
-            this.setState((state) => ({
+            this.setState({
               artifactInProgressName: value,
-            }));
+            });
           }}
         />
         <button

src/plugins/artifact/editor/ArtifactGraphEditor.test.js

@@ -2,8 +2,6 @@
 
 import React from "react";
 import {shallow} from "enzyme";
-import enzymeToJSON from "enzyme-to-json";
-import stringify from "json-stable-stringify";
 
 import {Graph} from "../../../core/graph";
 import {ArtifactGraphEditor} from "./ArtifactGraphEditor";

src/plugins/artifact/editor/ContributionList.js

@@ -2,7 +2,6 @@
 
 import React from "react";
 
-import type {Address} from "../../../core/address";
 import type {Node} from "../../../core/graph";
 import {AdapterSet} from "./adapterSet";
 import {Graph} from "../../../core/graph";
@@ -100,7 +99,7 @@ export class ContributionList extends React.Component<Props, State> {
               node.address.type === typeFilter.type
             );
           }
-        : (node) => true;
+        : (_) => true;
       return (
         <table>
           <thead>

src/plugins/artifact/editor/SettingsConfig.js

@@ -47,9 +47,7 @@ export class SettingsConfig extends React.Component<Props, State> {
             onChange={(e) => {
               const value = e.target.value;
               this.setState(
-                (state) => ({
-                  githubApiToken: value,
-                }),
+                {githubApiToken: value},
                 this._updateSettings.bind(this)
               );
             }}
@@ -63,9 +61,7 @@ export class SettingsConfig extends React.Component<Props, State> {
             onChange={(e) => {
               const value = e.target.value;
               this.setState(
-                (state) => ({
-                  repoOwner: value,
-                }),
+                {repoOwner: value},
                 this._updateSettings.bind(this)
               );
             }}
@@ -78,12 +74,7 @@ export class SettingsConfig extends React.Component<Props, State> {
             value={this.state.repoName}
             onChange={(e) => {
               const value = e.target.value;
-              this.setState(
-                (state) => ({
-                  repoName: value,
-                }),
-                this._updateSettings.bind(this)
-              );
+              this.setState({repoName: value}, this._updateSettings.bind(this));
             }}
           />
         </label>

src/plugins/git/loadRepository.js

@@ -77,10 +77,10 @@ function loadTree(git: GitDriver, treeHash: Hash): Tree {
   git(["ls-tree", "--full-tree", "-z", treeHash])
     .split("\0")
     .filter((line) => line.length > 0)
-    .map((line) => {
+    .forEach((line) => {
       // See `git help ls-tree`, section OUTPUT FORMAT, for details.
       const [metadata, name] = line.split("\t");
-      const [mode, type, hash] = metadata.split(" ");
+      const [_unused_mode, type, hash] = metadata.split(" ");
       if (type !== "blob" && type !== "commit" && type !== "tree") {
         throw new Error(
           `entry ${treeHash}[${JSON.stringify(name)}] ` +

src/plugins/git/loadRepository.test.js

@@ -3,7 +3,6 @@
 import tmp from "tmp";
 
 import {createExampleRepo} from "./demoData/exampleRepo";
-import {makeUtils} from "./gitUtils";
 import {loadRepository} from "./loadRepository";
 
 const cleanups: (() => void)[] = [];

src/plugins/github/api.test.js

@@ -79,10 +79,14 @@ describe("GitHub porcelain API", () => {
 
   describe("type coercion", () => {
     it("type coercion works when typed correctly", () => {
-      const issue: Issue = Issue.from(issueOrPRByNumber(1));
-      const pr: PullRequest = PullRequest.from(issueOrPRByNumber(3));
-      const author: Author = Author.from(issueOrPRByNumber(3).authors()[0]);
-      const comment: Comment = Comment.from(issueOrPRByNumber(2).comments()[0]);
+      const _unused_issue: Issue = Issue.from(issueOrPRByNumber(1));
+      const _unused_pr: PullRequest = PullRequest.from(issueOrPRByNumber(3));
+      const _unused_author: Author = Author.from(
+        issueOrPRByNumber(3).authors()[0]
+      );
+      const _unused_comment: Comment = Comment.from(
+        issueOrPRByNumber(2).comments()[0]
+      );
     });
     it("type coercion throws error when typed incorrectly", () => {
       expect(() => PullRequest.from(issueOrPRByNumber(1))).toThrowError(

src/plugins/github/graphql.js

@@ -788,7 +788,6 @@ function reviewCommentsFragment(): FragmentDefinition {
  * fetch more pages of specific entity types.
  */
 export function createFragments(): FragmentDefinition[] {
-  const b = build;
   return [
     whoamiFragment(),
     issuesFragment(),

src/plugins/github/graphql.test.js

@@ -2,7 +2,6 @@
 
 import type {Continuation} from "./graphql";
 import {build} from "../../graphql/queries";
-import {stringify, multilineLayout} from "../../graphql/queries";
 import {
   PAGE_LIMIT,
   createQuery,

src/plugins/github/parser.js

@@ -23,7 +23,6 @@ import type {
   IssueJSON,
   CommentJSON,
   AuthorJSON,
-  PullRequestReviewCommentJSON,
 } from "./graphql";
 
 import type {Address} from "../../core/address";

src/plugins/github/types.js

@@ -126,10 +126,10 @@ export type EdgePayload =
   | ContainsEdgePayload
   | ReferencesEdgePayload;
 
-(function staticAssertions() {
+function _unused_staticAssertions() {
   // Check that node & edge payload types are exhaustive.
-  (x: NodeType): $Keys<NodeTypes> => x;
-  (x: EdgeType): $Keys<EdgeTypes> => x;
+  const _unused_exhaustiveNode = (x: NodeType): $Keys<NodeTypes> => x;
+  const _unused_exhaustiveEdge = (x: EdgeType): $Keys<EdgeTypes> => x;
 
   // Check that each type is associated with the correct ID type.
   // Doesn't work because of a Flow bug; should work if that bug is
@@ -142,4 +142,4 @@ export type EdgePayload =
   //   $ElementType<$ElementType<NodeTypes, T>, "id">,
   //   "type"
   // > => x;
-});
+}