diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 5ac3491..f176817 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -13,22 +13,33 @@ jobs:
     runs-on: ${{ matrix.os }}
     defaults:
       run:
-        shell: bash
+        shell: bash -l {0}
     strategy:
+      fail-fast: false
       matrix:
-        os: [ubuntu-latest]
-    
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+        vim:
+          - 'v9.0.2189'
+          - 'v8.2.4286'
+
     steps:
-      - uses: actions/checkout@v1.0.0
-      - name: Install dependencies
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+      - name: Install coverage dependencies
+        if: ${{ matrix.os == 'ubuntu-latest' }}
         run: |
           sudo apt-get update
-          sudo apt-get install -y libcurl4-openssl-dev libelf-dev libdw-dev cmake vim kcov
+          sudo apt-get install -y libcurl4-openssl-dev libelf-dev libdw-dev cmake kcov
+      - uses: thinca/action-setup-vim@v1
+        with:
+          vim_version: ${{ matrix.vim }}
+      - name: Ensure vim installed
+        run: vim --version
+      - name: Smoke test of vims
+        run: echo "Hello" | ./vims ''
       - name: Run tests
-        run: |
-          mkdir -p coverage
-          TEST_DIR=$(pwd)/test VIMS=./vims kcov coverage ./test/test.sh
-      - name: Upload coverage
-        run: bash <(curl -s https://codecov.io/bash) -s coverage
-
-
+        run: VIMS=$PWD/vims ./test/bats/bin/bats ./test/test.bats
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..b7efcb4
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,9 @@
+[submodule "test/bats"]
+	path = test/bats
+	url = https://github.com/bats-core/bats-core.git
+[submodule "test/test_helper/bats-support"]
+	path = test/test_helper/bats-support
+	url = https://github.com/bats-core/bats-support.git
+[submodule "test/test_helper/bats-assert"]
+	path = test/test_helper/bats-assert
+	url = https://github.com/bats-core/bats-assert.git
diff --git a/README.md b/README.md
index 594e733..14f80b0 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # vims 
 
-[![CI](https://github.com/MilesCranmer/vim-stream/actions/workflows/CI.yml/badge.svg)](https://github.com/MilesCranmer/vim-stream/actions/workflows/CI.yml) [![Codecov branch](https://img.shields.io/codecov/c/github/MilesCranmer/vim-stream/master.svg)](https://codecov.io/gh/MilesCranmer/vim-stream)
+[![CI](https://github.com/MilesCranmer/vim-stream/actions/workflows/CI.yml/badge.svg)](https://github.com/MilesCranmer/vim-stream/actions/workflows/CI.yml)
 
 ![Demo](https://i.imgur.com/dntK3MP.gif)
 
diff --git a/test/bats b/test/bats
new file mode 160000
index 0000000..3d3f63d
--- /dev/null
+++ b/test/bats
@@ -0,0 +1 @@
+Subproject commit 3d3f63d9772b98c88586ec0a66bd358a85d9b4a6
diff --git a/test/test.bats b/test/test.bats
new file mode 100755
index 0000000..8b5f101
--- /dev/null
+++ b/test/test.bats
@@ -0,0 +1,80 @@
+#!/usr/bin/env bats
+
+setup() {
+    load "test_helper/bats-support/load"
+    load "test_helper/bats-assert/load"
+
+    DIR=$(dirname "${BATS_TEST_FILENAME}")
+    TEST_DIR=${TEST_DIR:-$DIR}
+    VIMS=${VIMS:-$DIR/../vims}
+}
+
+teardown() {
+    rm -f .tmp
+}
+
+@test "Identity" {
+    run cat $TEST_DIR/test_files/python.py | run $VIMS '' > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/python.py
+    assert_output ""
+}
+
+@test "Move init to bottom" {
+    run cat $TEST_DIR/test_files/python.py | run $VIMS -e '^\s\+def __init__' 'V/^\\s\\+def\<enter>kdGp' | run cat > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/python_init_at_bottom.py
+    assert_output ""
+}
+
+@test "Print last 4 lines" {
+    run cat $TEST_DIR/test_files/python.py | run $VIMS -n '$-3,$p' | run cat > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/python_last_4_lines.py
+    assert_output ""
+}
+
+@test "Do one long 'simple' command" {
+    run cat $TEST_DIR/test_files/python.py | run $VIMS -s '/^class\<enter>O# This class is for Bifrost\<esc>Go\<enter># This file does not run!' | run cat > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/python_with_extra_comments.py
+    assert_output ""
+}
+
+@test "Do one short 'simple' command" {
+    run cat $TEST_DIR/test_files/python.py | run $VIMS -s 'x' | run cat > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/python_minus_one_char.py
+    assert_output ""
+}
+
+@test "Reverse a file with exe" {
+    run cat $TEST_DIR/test_files/python.py | run $VIMS -e '.*' ':m0\<enter>' | run cat > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/python_reversed.py
+    assert_output ""
+}
+
+@test "Reverse a file in normal mode" {
+    run cat $TEST_DIR/test_files/python.py | run $VIMS '%g/.*/m0' | run cat > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/python_reversed.py
+    assert_output ""
+}
+
+@test "Turn back off exe mode" {
+    run cat $TEST_DIR/test_files/numbers.txt | run $VIMS -e '^5$' 'dd' -t '%g/^3$/t$' | run cat > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/numbers_5_gone_3_bottom.txt
+    assert_output ""
+}
+
+@test "Run multi-mode commands" {
+    run cat $TEST_DIR/test_files/numbers.txt | run $VIMS -e '^5$' 'dd' -s ':%g/^3$/t$\<enter>' | run cat > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/numbers_5_gone_3_bottom.txt
+    assert_output ""
+}
+
+@test "Execute command on every line" {
+    run cat $TEST_DIR/test_files/numbers.txt | run $VIMS -l '10\<c-x>' > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/numbers_all_decreased.txt
+    assert_output ""
+}
+
+@test "Delete all numbers not 1" {
+    run cat $TEST_DIR/test_files/numbers.txt | run $VIMS -r '^1$' 'dd' > .tmp
+    run diff -b .tmp $TEST_DIR/test_files/numbers_delete_all_not_1.txt
+    assert_output ""
+}
diff --git a/test/test.sh b/test/test.sh
deleted file mode 100755
index db1c828..0000000
--- a/test/test.sh
+++ /dev/null
@@ -1,91 +0,0 @@
-#!/bin/sh
-# From http://tldp.org/LDP/abs/html/debugging.html
-VIMS=./vims
-
-assert ()
-{
-    E_PARAM_ERR=98
-    E_ASSERT_FAILED=99
-    if [ -z "$2" ]
-    then
-        return $E_PARAM_ERR
-    fi
-    POINTED_LINE_NO=$2
-    if [ ! -z "$1" ]
-    then
-        echo -n "- test assertion failed!"
-        echo -n " test $3, line $POINTED_LINE_NO, "
-        echo "diff between output and expected:"
-        echo "$1"
-        exit $E_ASSERT_FAILED
-    fi
-}
-
-cat $TEST_DIR/test_files/python.py | $VIMS '' > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/python.py)
-TEST_NUM=0
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to do a non-edit passed"
-
-cat $TEST_DIR/test_files/python.py | $VIMS -e '^\s\+def __init__' 'V/^\\s\\+def\<enter>kdGp' | cat > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/python_init_at_bottom.py)
-TEST_NUM=1
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to move init to bottom passed"
-
-cat $TEST_DIR/test_files/python.py | $VIMS -n '$-3,$p' | cat > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/python_last_4_lines.py)
-TEST_NUM=2
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to print last 4 lines passed"
-
-cat $TEST_DIR/test_files/python.py | $VIMS -s '/^class\<enter>O# This class is for Bifrost\<esc>Go\<enter># This file does not run!' | cat > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/python_with_extra_comments.py)
-TEST_NUM=3
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to do one long 'simple' command passed"
-
-cat $TEST_DIR/test_files/python.py | $VIMS -s 'x' | cat > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/python_minus_one_char.py)
-TEST_NUM=4
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to do one short 'simple' command passed"
-
-cat $TEST_DIR/test_files/python.py | $VIMS -e '.*' ':m0\<enter>' | cat > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/python_reversed.py)
-TEST_NUM=5
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to reverse a file with exe passed"
-
-cat $TEST_DIR/test_files/python.py | $VIMS '%g/.*/m0' | cat > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/python_reversed.py)
-TEST_NUM=6
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to reverse a file in normal mode passed"
-
-cat $TEST_DIR/test_files/numbers.txt | $VIMS -e '^5$' 'dd' -t '%g/^3$/t$' | cat > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/numbers_5_gone_3_bottom.txt)
-TEST_NUM=7
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to turn back off exe mode passed"
-
-cat $TEST_DIR/test_files/numbers.txt | $VIMS -e '^5$' 'dd' -s ':%g/^3$/t$\<enter>' | cat > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/numbers_5_gone_3_bottom.txt)
-TEST_NUM=8
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to run multi-mode commands passed"
-
-cat $TEST_DIR/test_files/numbers.txt | $VIMS -l '10\<c-x>' > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/numbers_all_decreased.txt)
-TEST_NUM=9
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to execute command on every line passed"
-
-cat $TEST_DIR/test_files/numbers.txt | $VIMS -r '^1$' 'dd' > .tmp
-DIFF=$(diff -b .tmp $TEST_DIR/test_files/numbers_delete_all_not_1.txt)
-TEST_NUM=10
-assert "$DIFF" $LINENO $TEST_NUM
-echo "+ test $TEST_NUM to delete all numbers not 1 passed"
-
-echo "+ tests all passed"
-rm .tmp
diff --git a/test/test_helper/bats-assert b/test/test_helper/bats-assert
new file mode 160000
index 0000000..e2d855b
--- /dev/null
+++ b/test/test_helper/bats-assert
@@ -0,0 +1 @@
+Subproject commit e2d855bc78619ee15b0c702b5c30fb074101159f
diff --git a/test/test_helper/bats-support b/test/test_helper/bats-support
new file mode 160000
index 0000000..9bf10e8
--- /dev/null
+++ b/test/test_helper/bats-support
@@ -0,0 +1 @@
+Subproject commit 9bf10e876dd6b624fe44423f0b35e064225f7556