diff --git a/Cargo.lock b/Cargo.lock
index 06a6ea8d..a9f3a1cb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "anyhow"
 version = "1.0.44"
@@ -170,6 +179,16 @@ dependencies = [
  "clap",
 ]
 
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d82cfc11ce7f2c3faef78d8a684447b40d503d9681acebed6cb728d45940c4db"
+dependencies = [
+ "cfg-if",
+ "lazy_static",
+]
+
 [[package]]
 name = "difflib"
 version = "0.4.0"
@@ -215,6 +234,12 @@ version = "1.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
 
+[[package]]
+name = "fnv"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
+
 [[package]]
 name = "funty"
 version = "1.1.0"
@@ -238,6 +263,19 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
 
+[[package]]
+name = "globset"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "10463d9ff00a2a068db14231982f5132edebad0d7660cd956a1c30292dbcbfbd"
+dependencies = [
+ "aho-corasick",
+ "bstr",
+ "fnv",
+ "log",
+ "regex",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.11.2"
@@ -262,6 +300,24 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "ignore"
+version = "0.4.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "713f1b139373f96a2e0ce3ac931cd01ee973c3c5dd7c40c0c2efe96ad2b6751d"
+dependencies = [
+ "crossbeam-utils",
+ "globset",
+ "lazy_static",
+ "log",
+ "memchr",
+ "regex",
+ "same-file",
+ "thread_local",
+ "walkdir",
+ "winapi-util",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.7.0"
@@ -306,6 +362,15 @@ version = "0.2.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dd8f7255a17a627354f321ef0055d63b898c6fb27eff628af4d1b66b7331edf6"
 
+[[package]]
+name = "log"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "memchr"
 version = "2.4.1"
@@ -334,6 +399,12 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "once_cell"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "692fcb63b64b1758029e0a96ee63e049ce8c5948587f2f7208df04625e5f6b56"
+
 [[package]]
 name = "ordered-float"
 version = "2.8.0"
@@ -489,12 +560,29 @@ dependencies = [
  "redox_syscall",
 ]
 
+[[package]]
+name = "regex"
+version = "1.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
 [[package]]
 name = "regex-automata"
 version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c230d73fb8d8c1b9c0b3135c5142a8acee3a0558fb8db5cf1cb65f8d7862132"
 
+[[package]]
+name = "regex-syntax"
+version = "0.6.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
+
 [[package]]
 name = "remove_dir_all"
 version = "0.5.3"
@@ -532,6 +620,15 @@ version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e"
 
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "semver"
 version = "1.0.4"
@@ -631,6 +728,15 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "thread_local"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8018d24e04c95ac8790716a5987d0fec4f8b27249ffa0f7d33f1369bdfb88cbd"
+dependencies = [
+ "once_cell",
+]
+
 [[package]]
 name = "unicode-segmentation"
 version = "1.8.0"
@@ -670,6 +776,17 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "walkdir"
+version = "2.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "808cf2735cd4b6866113f648b791c6adc5714537bc222d9347bb203386ffda56"
+dependencies = [
+ "same-file",
+ "winapi",
+ "winapi-util",
+]
+
 [[package]]
 name = "wasi"
 version = "0.10.2+wasi-snapshot-preview1"
@@ -719,6 +836,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "clap",
+ "ignore",
  "shell-words",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index e22b3b61..08b2d477 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,6 +9,9 @@ license = "MIT"
 keywords = ["cli"]
 categories = ["command-line-utilities", "filesystem"]
 
+[badges]
+maintenance = { status = "actively-developed" }
+
 [workspace]
 members = ["xtask/"]
 
diff --git a/shell.nix b/shell.nix
index dcee1a30..2b081fc2 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,9 +1,11 @@
 let
-  rust = import (builtins.fetchTarball "https://github.com/oxalica/rust-overlay/archive/ad311f5bb5c5ef475985f1e0f264e831470a8510.tar.gz");
+  rust = import (builtins.fetchTarball
+    "https://github.com/oxalica/rust-overlay/archive/ad311f5bb5c5ef475985f1e0f264e831470a8510.tar.gz");
   pkgs = import <nixpkgs> { overlays = [ rust ]; };
-  pkgs-latest = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/b4692e4197869c42c46d77e31af7e687e1892f55.tar.gz") {};
-in
-pkgs.mkShell {
+  pkgs-latest = import (fetchTarball
+    "https://github.com/NixOS/nixpkgs/archive/b4692e4197869c42c46d77e31af7e687e1892f55.tar.gz")
+    { };
+in pkgs.mkShell {
   buildInputs = [
     # Rust
     pkgs.rust-bin.stable.latest.default
@@ -21,6 +23,7 @@ pkgs.mkShell {
     # Tools
     pkgs-latest.cargo-audit
     pkgs-latest.mandoc
+    pkgs-latest.nixfmt
     pkgs-latest.nodePackages.markdownlint-cli
     pkgs-latest.python3Packages.black
     pkgs-latest.python3Packages.mypy
diff --git a/src/shell.rs b/src/shell.rs
index ba3f6a23..6199a049 100644
--- a/src/shell.rs
+++ b/src/shell.rs
@@ -321,16 +321,7 @@ mod tests {
         let mut source = Xonsh(&opts).render().unwrap();
         source.push('\n');
 
-        let tempdir = tempfile::tempdir().unwrap();
-        let tempdir = tempdir.path().to_str().unwrap();
-
-        Command::new("pylint")
-            .args(&["--from-stdin", "zoxide"])
-            .env("HOME", tempdir)
-            .write_stdin(source)
-            .assert()
-            .success()
-            .stderr("");
+        Command::new("pylint").args(&["--from-stdin", "zoxide"]).write_stdin(source).assert().success().stderr("");
     }
 
     #[rstest]
diff --git a/tests/completion.rs b/tests/completions.rs
similarity index 96%
rename from tests/completion.rs
rename to tests/completions.rs
index 5e5c2883..56975d8e 100644
--- a/tests/completion.rs
+++ b/tests/completions.rs
@@ -1,4 +1,4 @@
-//! Syntax checking for auto-generated shell completions.
+//! Test clap generated completions.
 #![cfg(feature = "nix")]
 
 use assert_cmd::Command;
diff --git a/tests/man.rs b/tests/man.rs
deleted file mode 100644
index faf1e64e..00000000
--- a/tests/man.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-//! Syntax checking for manpages.
-#![cfg(feature = "nix")]
-
-use assert_cmd::Command;
-
-use std::fs;
-
-#[test]
-fn mandoc_lint() {
-    let paths = fs::read_dir("man")
-        .unwrap()
-        .filter_map(|entry| {
-            let path = entry.unwrap().path();
-            if path.is_file() && path.extension() == Some("1".as_ref()) {
-                Some(path.to_str().unwrap().to_string())
-            } else {
-                None
-            }
-        })
-        .collect::<Vec<_>>();
-    Command::new("mandoc")
-        .args(&["-man", "-Wall", "-Tlint", "--"])
-        .args(&paths)
-        .assert()
-        .success()
-        .stdout("")
-        .stderr("");
-}
diff --git a/xtask/Cargo.toml b/xtask/Cargo.toml
index 773ca7d8..68523405 100644
--- a/xtask/Cargo.toml
+++ b/xtask/Cargo.toml
@@ -7,4 +7,5 @@ publish = false
 [dependencies]
 anyhow = "1.0.32"
 clap = "=3.0.0-beta.4"
+ignore = "0.4.18"
 shell-words = "1.0.0"
diff --git a/xtask/src/main.rs b/xtask/src/main.rs
index 90b5a083..6de70d47 100644
--- a/xtask/src/main.rs
+++ b/xtask/src/main.rs
@@ -1,5 +1,6 @@
 use anyhow::{bail, Context, Result};
 use clap::Clap;
+use ignore::Walk;
 
 use std::env;
 use std::ffi::OsStr;
@@ -9,15 +10,16 @@ use std::process::{self, Command};
 fn main() -> Result<()> {
     let nix_enabled = enable_nix();
 
+    let dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    let dir = dir.parent().with_context(|| format!("could not find workspace root: {}", dir.display()))?;
+    env::set_current_dir(dir).with_context(|| format!("could not set current directory: {}", dir.display()))?;
+
     let app = App::parse();
     match app {
-        App::Audit => run_audit(&[] as &[&str])?,
-        App::Check => run_check(&[] as &[&str])?,
-        App::Clippy => run_clippy(&[] as &[&str])?,
         App::CI => run_ci(nix_enabled)?,
-        App::Fmt => run_fmt(&[] as &[&str])?,
-        App::Markdownlint => run_markdownlint()?,
-        App::Test { name } => run_test(nix_enabled, &[name])?,
+        App::Fmt { check } => run_fmt(nix_enabled, check)?,
+        App::Lint => run_lint(nix_enabled)?,
+        App::Test { name } => run_tests(nix_enabled, &name)?,
     }
 
     Ok(())
@@ -25,12 +27,12 @@ fn main() -> Result<()> {
 
 #[derive(Clap)]
 enum App {
-    Audit,
-    Check,
     CI,
-    Clippy,
-    Fmt,
-    Markdownlint,
+    Fmt {
+        #[clap(long)]
+        check: bool,
+    },
+    Lint,
     Test {
         #[clap(default_value = "")]
         name: String,
@@ -52,44 +54,76 @@ impl CommandExt for &mut Command {
     }
 }
 
-fn run_audit<S: AsRef<OsStr>>(args: &[S]) -> Result<()> {
-    Command::new("cargo").args(&["audit", "--deny=warnings"]).args(args)._run()
-}
+fn run_ci(nix_enabled: bool) -> Result<()> {
+    let color: &[&str] = if is_ci() { &["--color=always"] } else { &[] };
+    Command::new("cargo").args(&["check", "--all-features"]).args(color)._run()?;
 
-fn run_check<S: AsRef<OsStr>>(args: &[S]) -> Result<()> {
-    Command::new("cargo").args(&["check", "--all-features", "--all-targets", "--workspace"]).args(args)._run()
+    run_fmt(nix_enabled, true)?;
+    run_lint(nix_enabled)?;
+    run_tests(nix_enabled, "")
 }
 
-fn run_clippy<S: AsRef<OsStr>>(args: &[S]) -> Result<()> {
-    Command::new("cargo").args(&["clippy", "--all-features", "--all-targets"]).args(args)._run()
-}
+fn run_fmt(nix_enabled: bool, check: bool) -> Result<()> {
+    // Run cargo-fmt.
+    let color: &[&str] = if is_ci() { &["--color=always"] } else { &[] };
+    let check_args: &[&str] = if check { &["--check", "--files-with-diff"] } else { &[] };
+    Command::new("cargo").args(&["fmt", "--all", "--"]).args(color).args(check_args)._run()?;
 
-fn run_ci(nix_enabled: bool) -> Result<()> {
-    let color = if env::var_os("CI").is_some() { "--color=always" } else { "--color=auto" };
-    run_fmt(&["--check", color, "--files-with-diff"])?;
-    run_check(&[color])?;
-    run_clippy(&[color])?;
-    run_test(nix_enabled, &[color, "--no-fail-fast"])?;
+    // Run nixfmt.
     if nix_enabled {
-        run_audit(&[] as &[&str])?; // FIXME: add "color" when cargo-audit 0.15.3 is released
-        run_markdownlint()?;
+        for result in Walk::new("./") {
+            let entry = result.unwrap();
+            let path = entry.path();
+            if path.is_file() && path.extension() == Some(OsStr::new("nix")) {
+                let check_args: &[&str] = if check { &["--check"] } else { &[] };
+                Command::new("nixfmt").args(check_args).arg("--").arg(path)._run()?;
+            }
+        }
     }
+
     Ok(())
 }
 
-fn run_fmt<S: AsRef<OsStr>>(rustfmt_args: &[S]) -> Result<()> {
-    Command::new("cargo").args(&["fmt", "--all", "--"]).args(rustfmt_args)._run()
+fn run_lint(nix_enabled: bool) -> Result<()> {
+    // Run cargo-clippy.
+    let color: &[&str] = if is_ci() { &["--color=always"] } else { &[] };
+    Command::new("cargo").args(&["clippy", "--all-features", "--all-targets"]).args(color)._run()?;
+
+    if nix_enabled {
+        // Run cargo-audit.
+        let color: &[&str] = if is_ci() { &["--color=always"] } else { &[] };
+        Command::new("cargo").args(&["audit", "--deny=warnings"]).args(color)._run()?;
+
+        // Run markdownlint.
+        for result in Walk::new("./") {
+            let entry = result.unwrap();
+            let path = entry.path();
+            if path.is_file() && path.extension() == Some(OsStr::new("md")) {
+                Command::new("markdownlint").arg(path)._run()?;
+            }
+        }
+
+        // Run mandoc with linting enabled.
+        for result in Walk::new("./man/") {
+            let entry = result.unwrap();
+            let path = entry.path();
+            if path.is_file() && path.extension() == Some(OsStr::new("1")) {
+                Command::new("mandoc").args(&["-man", "-Wall", "-Tlint", "--"]).arg(path)._run()?;
+            }
+        }
+    }
+
+    Ok(())
 }
 
-fn run_markdownlint() -> Result<()> {
-    Command::new("markdownlint").args(&["--ignore-path=.gitignore", "."])._run()
+fn run_tests(nix_enabled: bool, name: &str) -> Result<()> {
+    let color: &[&str] = if is_ci() { &["--color=always"] } else { &[] };
+    let features: &[&str] = if nix_enabled { &["--all-features"] } else { &[] };
+    Command::new("cargo").args(&["test", "--no-fail-fast", "--workspace"]).args(color).args(features).arg(name)._run()
 }
 
-fn run_test<S: AsRef<OsStr>>(nix_enabled: bool, args: &[S]) -> Result<()> {
-    Command::new("cargo")
-        .args(&["test", "--workspace", if nix_enabled { "--features=nix" } else { "" }])
-        .args(args)
-        ._run()
+fn is_ci() -> bool {
+    env::var_os("CI").is_some()
 }
 
 fn enable_nix() -> bool {