test: add uutests-based smoke tests

Cargo.toml

@@ -45,6 +45,10 @@ rustix = { version = "1.1.4", default-features = false, features = ["process"]}
 tracing-subscriber = { version = "0.3.23", features = ["env-filter"] }
 tracing-error = "0.2.1"
 
+[dev-dependencies]
+ctor = "0.4"
+uutests = "0.8"
+
 [profile.release]
 lto = true
 panic = "abort"

tests/awk.rs

@@ -1 +1,16 @@
+use std::env;
 
+pub const TESTS_BINARY: &str = env!("CARGO_BIN_EXE_awk");
+
+#[ctor::ctor]
+fn init() {
+    unsafe {
+        env::set_var("UUTESTS_BINARY_PATH", TESTS_BINARY);
+        env::remove_var("UUTESTS_UTIL_NAME");
+        env::set_var("UUTESTS_UTIL_NAME", "");
+        env::set_var("UUTILS_MULTICALL", "0");
+    }
+}
+
+#[path = "by-util/test_awk.rs"]
+mod test_awk;

tests/by-util/test_awk.rs

@@ -0,0 +1,12 @@
+use uutests::new_ucmd;
+
+#[test]
+fn empty_program_succeeds() {
+    new_ucmd!().arg("").succeeds();
+}
+
+#[test]
+#[ignore = "parser does not yet support print/field expressions"]
+fn print_first_field() {
+    new_ucmd!().arg("{ print $1 }").succeeds();
+}