Add GNU ls compatibility tests

This adds an initial set of integration tests that make sure that we
generate the same styles as GNU `ls`.

Related: #48

.github/workflows/CICD.yml

@@ -163,8 +163,8 @@ jobs:
       shell: bash
       run: |
         # test only library unit tests and binary for arm-type targets
-        unset CARGO_TEST_OPTIONS
-        unset CARGO_TEST_OPTIONS ; case ${{ matrix.job.target }} in arm-* | aarch64-*) CARGO_TEST_OPTIONS="--all-features --lib --bin ${{ needs.crate_metadata.outputs.name }}" ;; esac;
+        CARGO_TEST_OPTIONS="--all-features"
+        case ${{ matrix.job.target }} in arm-* | aarch64-*) CARGO_TEST_OPTIONS="--all-features --lib --bin ${{ needs.crate_metadata.outputs.name }}" ;; esac;
         echo "CARGO_TEST_OPTIONS=${CARGO_TEST_OPTIONS}" >> $GITHUB_OUTPUT
 
     - name: Run tests

Cargo.toml

@@ -38,3 +38,8 @@ required-features = ["nu-ansi-term"]
 lto = true
 strip = true
 codegen-units = 1
+
+[[test]]
+name = "integration_tests"
+path = "tests/integration_tests.rs"
+required-features = ["nu-ansi-term"]

tests/integration_tests.rs

@@ -0,0 +1,79 @@
+use lscolors::LsColors;
+use lscolors::Style;
+
+use std::process::Command;
+
+fn get_ls_style(ls_colors_env: Option<&str>, path: &str) -> Option<Style> {
+    let output_gnu_ls = {
+        let mut cmd = Command::new("ls");
+
+        cmd.arg("--color=always").arg("--directory").arg(path);
+
+        if let Some(ls_colors_env) = ls_colors_env {
+            cmd.env("LS_COLORS", ls_colors_env);
+        } else {
+            cmd.env_remove("LS_COLORS");
+        }
+
+        cmd.output().unwrap().stdout
+    };
+
+    let output_gnu_ls = String::from_utf8(output_gnu_ls).expect("valid UTF-8 output from ls");
+
+    let style_str = output_gnu_ls.trim().trim_start_matches("\x1b[0m\x1b[");
+
+    let end_of_ansi_code = style_str.find(&format!("m{path}", path = path))?;
+    let style_str = &style_str[0..end_of_ansi_code];
+
+    // For a proper integration test, we would ideally compare the output on an ANSI-escape-sequence level.
+    // Unfortunately, those are not unambiguous. Both \x1b[1m as well as \x1b[01m render something in bold.
+    // So instead, we trust our escape sequence parser (and its tests) and compare the output on a `Style`
+    // level.
+    Style::from_ansi_sequence(&style_str)
+}
+
+fn assert_style_matches_ls(lscolors: &LsColors, ls_colors_env: Option<&str>, path: &str) {
+    let lscolors_style = lscolors.style_for_path(path);
+    let ls_style = get_ls_style(ls_colors_env, path);
+
+    assert_eq!(lscolors_style, ls_style.as_ref());
+}
+
+#[cfg(unix)]
+#[test]
+fn gnu_ls_compatibility_no_ls_colors() {
+    let lscolors = LsColors::default();
+
+    assert_style_matches_ls(&lscolors, None, "tests/");
+    assert_style_matches_ls(&lscolors, None, "Cargo.toml");
+}
+
+#[cfg(unix)]
+#[test]
+fn gnu_ls_compatibility_custom_ls_colors() {
+    {
+        let ls_colors_env = "*.toml=01;31";
+        let lscolors = LsColors::from_string(ls_colors_env);
+
+        assert_style_matches_ls(&lscolors, Some(ls_colors_env), "tests/");
+        assert_style_matches_ls(&lscolors, Some(ls_colors_env), "Cargo.toml");
+    }
+    {
+        let ls_colors_env = "*.toml=01;31:di=32";
+        let lscolors = LsColors::from_string(ls_colors_env);
+
+        assert_style_matches_ls(&lscolors, Some(ls_colors_env), "tests/");
+        assert_style_matches_ls(&lscolors, Some(ls_colors_env), "Cargo.toml");
+    }
+}
+
+#[cfg(unix)]
+#[test]
+fn gnu_ls_compatibility_duplicate_entries() {
+    {
+        let ls_colors_env = "*.toml=31:*.toml=32";
+        let lscolors = LsColors::from_string(ls_colors_env);
+
+        assert_style_matches_ls(&lscolors, Some(ls_colors_env), "Cargo.toml");
+    }
+}