dep-time-travel: use older versions of dependencies

for tests against older ESLint versions.

.travis.yml

@@ -32,6 +32,7 @@ matrix:
     node_js: 6
   - env: PACKAGE=resolvers/webpack
     node_js: 4
+
   - os: osx
     env: ESLINT_VERSION=5
     node_js: 10
@@ -54,7 +55,7 @@ before_install:
   - 'if [ -n "${PACKAGE-}" ]; then cd "${PACKAGE}"; fi'
 install:
   - npm install
-  - npm install --no-save eslint@$ESLINT_VERSION --ignore-scripts || true
+  - 'if [ -n "${ESLINT_VERSION}" ]; then ./tests/dep-time-travel.sh; fi'
 
 script:
   - 'npm test'

tests/dep-time-travel.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+# expected: ESLINT_VERSION numeric env var
+
+npm install --no-save eslint@$ESLINT_VERSION --ignore-scripts || true
+
+# use these alternate typescript dependencies for ESLint < v4
+if [[ "$ESLINT_VERSION" -lt "4" ]]; then
+  echo "Downgrading babel-eslint..."
+  npm i --no-save babel-eslint@8.0.3
+
+  echo "Downgrading TypeScript dependencies..."
+  npm i --no-save typescript-eslint-parser@15 typescript@2.8.1
+fi
+
+# typescript-eslint-parser 1.1.1+ is not compatible with node 6
+if [[ "$TRAVIS_NODE_VERSION" -lt "8" ]]; then
+  echo "Downgrading eslint-import-resolver-typescript..."
+  npm i --no-save eslint-import-resolver-typescript@1.0.2
+fi

tests/src/core/getExports.js

@@ -3,7 +3,7 @@ import ExportMap from '../../../src/ExportMap'
 
 import * as fs from 'fs'
 
-import { getFilename, skipESLints } from '../utils'
+import { getFilename } from '../utils'
 import * as unambiguous from 'eslint-module-utils/unambiguous'
 
 describe('ExportMap', function () {
@@ -310,7 +310,7 @@ describe('ExportMap', function () {
 
   })
 
-  skipESLints([2, 3])('alternate parsers', function () {
+  context('alternate parsers', function () {
 
     const configs = [
       // ['string form', { 'typescript-eslint-parser': '.ts' }],

tests/src/rules/named.js

@@ -1,4 +1,4 @@
-import { test, SYNTAX_CASES, skipESLints } from '../utils'
+import { test, SYNTAX_CASES } from '../utils'
 import { RuleTester } from 'eslint'
 
 import { CASE_SENSITIVE_FS } from 'eslint-module-utils/resolve'
@@ -254,7 +254,7 @@ ruleTester.run('named (export *)', rule, {
 })
 
 
-skipESLints([2, 3])("Typescript", function () {
+context("Typescript", function () {
   // Typescript
   ruleTester.run("named", rule, {
     valid: [

tests/src/utils.js

@@ -29,17 +29,6 @@ export function getFilename(file) {
   return path.join(__dirname, '..', 'files', file || 'foo.js')
 }
 
-/**
- * skip tests iff ESLINT_VERSION is in provided `versions` array
- */
-export function skipESLints(versions) {
-  if (versions.indexOf(+process.env.ESLINT_VERSION) === -1) {
-    return describe
-  } else {
-    return describe.skip
-  }
-}
-
 /**
  * to be added as valid cases just to ensure no nullable fields are going
  * to crash at runtime