diff --git a/tests/fixtures/10000-unique-keys/input.txt b/tests/fixtures/10000_unique_keys/input.txt
similarity index 100%
rename from tests/fixtures/10000-unique-keys/input.txt
rename to tests/fixtures/10000_unique_keys/input.txt
diff --git a/tests/fixtures/10000-unique-keys/output.txt b/tests/fixtures/10000_unique_keys/output.txt
similarity index 100%
rename from tests/fixtures/10000-unique-keys/output.txt
rename to tests/fixtures/10000_unique_keys/output.txt
diff --git a/tests/fixtures/complex-utf8/input.txt b/tests/fixtures/complex_utf8/input.txt
similarity index 100%
rename from tests/fixtures/complex-utf8/input.txt
rename to tests/fixtures/complex_utf8/input.txt
diff --git a/tests/fixtures/complex-utf8/output.txt b/tests/fixtures/complex_utf8/output.txt
similarity index 100%
rename from tests/fixtures/complex-utf8/output.txt
rename to tests/fixtures/complex_utf8/output.txt
diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index e69de29..eb928c1 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -0,0 +1,120 @@
+use assert_cmd::Command;
+
+#[test]
+fn test_1() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/1/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/1/output.txt"));
+}
+
+#[test]
+fn test_2() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/2/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/2/output.txt"));
+}
+
+#[test]
+fn test_3() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/3/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/3/output.txt"));
+}
+
+#[test]
+fn test_10() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/10/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/10/output.txt"));
+}
+
+#[test]
+fn test_20() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/20/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/20/output.txt"));
+}
+
+#[test]
+fn test_10000_unique_keys() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/10000_unique_keys/input.txt"]);
+    command.assert().success().stdout(include_str!(
+        "../tests/fixtures/10000_unique_keys/output.txt"
+    ));
+}
+
+#[test]
+fn test_boundaries() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/boundaries/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/boundaries/output.txt"));
+}
+
+#[test]
+fn test_complex_utf8() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/complex_utf8/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/complex_utf8/output.txt"));
+}
+
+#[test]
+fn test_dot() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/dot/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/dot/output.txt"));
+}
+
+#[test]
+fn test_rounding() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/rounding/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/rounding/output.txt"));
+}
+
+#[test]
+fn test_short() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/short/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/short/output.txt"));
+}
+
+#[test]
+fn test_shortest() {
+    let mut command = Command::cargo_bin(env!("CARGO_PKG_NAME")).unwrap();
+    command.args(["tests/fixtures/shortest/input.txt"]);
+    command
+        .assert()
+        .success()
+        .stdout(include_str!("../tests/fixtures/shortest/output.txt"));
+}