diff --git a/.github/workflows/node-4+.yml b/.github/workflows/node-4+.yml
index d4035d267..f2498807c 100644
--- a/.github/workflows/node-4+.yml
+++ b/.github/workflows/node-4+.yml
@@ -83,7 +83,7 @@ jobs:
           skip-ls-check: true
       - run: npm run pretest
       - run: npm run tests-only
-      - run: npm run coveralls
+      - uses: codecov/codecov-action@v1
 
   node:
     name: 'node 4+'
diff --git a/.github/workflows/packages.yml b/.github/workflows/packages.yml
index 79bd1ce46..e7302faea 100644
--- a/.github/workflows/packages.yml
+++ b/.github/workflows/packages.yml
@@ -43,6 +43,7 @@ jobs:
           after_install: npm run copy-metafiles && ./tests/dep-time-travel.sh && cd ${{ matrix.package }} && npm install
           skip-ls-check: true
       - run: cd ${{ matrix.package }} && npm run tests-only
+      - uses: codecov/codecov-action@v1
 
   packages:
     name: 'packages: all tests'
diff --git a/.nycrc b/.nycrc
index 8147f3871..20bcfca22 100644
--- a/.nycrc
+++ b/.nycrc
@@ -1,7 +1,7 @@
 {
 	"all": true,
 	"check-coverage": false,
-	"reporter": ["text-summary", "text", "html", "json"],
+	"reporter": ["text-summary", "lcov", "text", "html", "json"],
 	"require": [
 		"babel-register"
 	],
diff --git a/.travis.yml b/.travis.yml
index 583a41197..c289a39e4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -36,4 +36,4 @@ script:
   - npm run tests-only
 
 after_success:
-  - npm run coveralls
+  - bash <(curl -s https://codecov.io/bash)
diff --git a/appveyor.yml b/appveyor.yml
index de79234eb..c728414d4 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -5,28 +5,31 @@ configuration:
 # Test against this version of Node.js
 environment:
   matrix:
+    - nodejs_version: "16"
     - nodejs_version: "14"
     - nodejs_version: "12"
     - nodejs_version: "10"
     - nodejs_version: "8"
-  # - nodejs_version: "6"
-  # - nodejs_version: "4"
+    # - nodejs_version: "6"
+    # - nodejs_version: "4"
 
 image: Visual Studio 2019
 matrix:
   fast_finish: false
   exclude:
-    - configuration: WSL
-      nodejs_version: "10"
     - configuration: WSL
       nodejs_version: "8"
+    - configuration: WSL
+      nodejs_version: "6"
+    - configuration: WSL
+      nodejs_version: "4"
 
-  # allow_failures:
-  #   - nodejs_version: "4" # for eslint 5
+  allow_failures:
+    - nodejs_version: "4" # for eslint 5
 
-# platform:
-#   - x86
-#   - x64
+platform:
+  - x86
+  - x64
 
 # Initialization scripts. (runs before repo cloning)
 init:
@@ -35,14 +38,26 @@ init:
       if ($env:nodejs_version -eq "4") {
         $env:NPM_VERSION="3"
       }
-      if ($env:nodejs_version -in @("8", "10", "12")) {
-        $env:NPM_VERSION="6.14.5"
+      if ($env:nodejs_version -in @("8")) {
+        $env:NPM_VERSION="6"
+      }
+      if ($env:nodejs_version -in @("10", "12", "14", "16")) {
+        $env:NPM_VERSION="6" # TODO: use npm 7
+        $env:NPM_CONFIG_LEGACY_PEER_DEPS="true"
       }
   - ps: >-
+      $env:ESLINT_VERSION="7";
       if ([int]$env:nodejs_version -le 8) {
         $env:ESLINT_VERSION="6"
       }
+      if ([int]$env:nodejs_version -le 7) {
+        $env:ESLINT_VERSION="5"
+      }
+      if ([int]$env:nodejs_version -le 6) {
+        $env:ESLINT_VERSION="4"
+      }
   - ps: $env:WINDOWS_NYC_VERSION = "15.0.1"
+  - ps: $env:TRAVIS_NODE_VERSION = $env:nodejs_version
 
   # Add `ci`-command to `PATH` for running commands either using cmd or wsl depending on the configuration
   - ps: $env:PATH += ";$(Join-Path $(pwd) "scripts")"
@@ -54,6 +69,8 @@ before_build:
 
   # Install dependencies
   - ci npm install
+  - ci npm run copy-metafiles
+  - bash ./tests/dep-time-travel.sh 2>&1
 
   # fix symlinks
   - git config core.symlinks true
@@ -99,9 +116,6 @@ test_script:
       $env:RESOLVERS = [string]::Join(";", $resolvers);
   - FOR %%G in ("%RESOLVERS:;=";"%") do ( pushd %%~G & ci npm test & popd )
 
-on_success:
-  - ci npm run coveralls
-
 # Configuration-specific steps
 for:
   - matrix:
@@ -127,6 +141,9 @@ for:
             }
           $env:RESOLVERS = [string]::Join(";", $resolvers);
       - IF DEFINED RESOLVERS FOR %%G in ("%RESOLVERS:;=";"%") do ( pushd %%~G & ci npm install --no-save nyc@%WINDOWS_NYC_VERSION% & popd )
+    # TODO: enable codecov for native windows builds
+    # on_success:
+      # - codecov
   - matrix:
       only:
         - configuration: WSL
@@ -136,5 +153,7 @@ for:
       - ps: $env:WSLENV += ":nodejs_version"
       - ps: wsl curl -sL 'https://deb.nodesource.com/setup_${nodejs_version}.x' `| sudo APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1 -E bash -
       - wsl sudo DEBIAN_FRONTEND=noninteractive apt install -y nodejs
+    on_success:
+      - ci bash <(curl -s https://codecov.io/bash)
 
 build: on
diff --git a/package.json b/package.json
index dd7cbcb35..7537df99a 100644
--- a/package.json
+++ b/package.json
@@ -25,14 +25,13 @@
     "watch": "npm run tests-only -- -- --watch",
     "pretest": "linklocal",
     "posttest": "eslint .",
-    "mocha": "cross-env BABEL_ENV=test nyc -s mocha",
+    "mocha": "cross-env BABEL_ENV=test nyc mocha",
     "tests-only": "npm run mocha tests/src",
     "test": "npm run tests-only",
     "test-compiled": "npm run prepublish && BABEL_ENV=testCompiled mocha --compilers js:babel-register tests/src",
     "test-all": "node --require babel-register ./scripts/testAll",
     "prepublishOnly": "safe-publish-latest && npm run build",
-    "prepublish": "not-in-publish || npm run prepublishOnly",
-    "coveralls": "nyc report --reporter lcovonly && coveralls < ./coverage/lcov.info"
+    "prepublish": "not-in-publish || npm run prepublishOnly"
   },
   "repository": {
     "type": "git",
@@ -69,7 +68,6 @@
     "babel-register": "^6.26.0",
     "babylon": "^6.18.0",
     "chai": "^4.3.4",
-    "coveralls": "^3.1.1",
     "cross-env": "^4.0.0",
     "eslint": "^2 || ^3 || ^4 || ^5 || ^6 || ^7.2.0",
     "eslint-import-resolver-node": "file:./resolvers/node",
diff --git a/resolvers/node/package.json b/resolvers/node/package.json
index 5e7e9dea7..51a7d49cc 100644
--- a/resolvers/node/package.json
+++ b/resolvers/node/package.json
@@ -9,8 +9,7 @@
   "scripts": {
     "prepublishOnly": "cp ../../{LICENSE,.npmrc} ./",
     "tests-only": "nyc mocha",
-    "test": "npm run tests-only",
-    "coveralls": "nyc report --reporter lcovonly && cd ../.. && coveralls < ./resolvers/node/coverage/lcov.info"
+    "test": "npm run tests-only"
   },
   "repository": {
     "type": "git",
@@ -35,7 +34,6 @@
   },
   "devDependencies": {
     "chai": "^3.5.0",
-    "coveralls": "^3.1.0",
     "mocha": "^3.5.3",
     "nyc": "^11.9.0"
   }
diff --git a/resolvers/webpack/package.json b/resolvers/webpack/package.json
index fd805af8b..bd6269e2f 100644
--- a/resolvers/webpack/package.json
+++ b/resolvers/webpack/package.json
@@ -6,9 +6,7 @@
   "scripts": {
     "prepublishOnly": "cp ../../{LICENSE,.npmrc} ./",
     "tests-only": "nyc mocha -t 5s",
-    "test": "npm run tests-only",
-    "report": "nyc report --reporter=html",
-    "coveralls": "nyc report --reporter lcovonly && cd ../.. && coveralls < ./resolvers/webpack/coverage/lcov.info"
+    "test": "npm run tests-only"
   },
   "files": [
     "index.js",
@@ -53,7 +51,6 @@
     "babel-preset-es2015-argon": "latest",
     "babel-register": "^6.26.0",
     "chai": "^3.5.0",
-    "coveralls": "^3.1.0",
     "mocha": "^3.5.3",
     "nyc": "^11.9.0",
     "webpack": "https://gist.github.com/ljharb/9cdb687f3806f8e6cb8a365d0b7840eb"
diff --git a/tests/dep-time-travel.sh b/tests/dep-time-travel.sh
index d6f5aedfc..2e2459576 100755
--- a/tests/dep-time-travel.sh
+++ b/tests/dep-time-travel.sh
@@ -2,7 +2,7 @@
 
 # expected: ESLINT_VERSION numeric env var
 
-echo "installing ${ESLINT_VERSION}..."
+echo "installing ${ESLINT_VERSION} in node ${TRAVIS_NODE_VERSION} with TS parser ${TS_PARSER:-default}..."
 
 export NPM_CONFIG_LEGACY_PEER_DEPS=true