corpus-core: make the stream contract hold under hostile input

crates/corpus-core/tests/cli.rs

@@ -0,0 +1,63 @@
+//! The schema command, as a consumer in another language would meet it.
+
+use std::process::{Command, Output};
+
+fn run(args: &[&str]) -> Output {
+    Command::new(env!("CARGO_BIN_EXE_corpus-core"))
+        .args(args)
+        .output()
+        .expect("the binary should run")
+}
+
+#[test]
+fn a_named_record_prints_its_schema() {
+    let out = run(&["schema", "doc"]);
+    assert_eq!(out.status.code(), Some(0));
+    let json: serde_json::Value = serde_json::from_slice(&out.stdout).expect("valid JSON");
+    assert_eq!(json["title"], "Doc");
+    assert!(out.stderr.is_empty(), "diagnostics leaked to stdout's side");
+}
+
+#[test]
+fn no_record_named_means_all_of_them() {
+    let out = run(&["schema"]);
+    assert_eq!(out.status.code(), Some(0));
+    let json: serde_json::Value = serde_json::from_slice(&out.stdout).expect("valid JSON");
+    for record in ["doc", "chunk", "hit"] {
+        assert!(json.get(record).is_some(), "missing {record}");
+    }
+}
+
+#[test]
+fn an_unknown_record_is_a_usage_error_with_nothing_on_stdout() {
+    let out = run(&["schema", "nope"]);
+    assert_eq!(out.status.code(), Some(64));
+    assert!(out.stdout.is_empty());
+    assert!(!out.stderr.is_empty());
+}
+
+#[test]
+fn arguments_that_mean_nothing_are_refused_rather_than_ignored() {
+    for args in [
+        vec![],
+        vec!["schema", "doc", "junk"],
+        vec!["nonsense"],
+        vec!["--json"],
+    ] {
+        let out = run(&args);
+        assert_eq!(out.status.code(), Some(64), "for {args:?}");
+    }
+}
+
+#[test]
+fn it_says_what_version_it_is() {
+    let out = run(&["--version"]);
+    assert_eq!(out.status.code(), Some(0));
+    let said = String::from_utf8(out.stdout).unwrap();
+    assert!(said.contains(env!("CARGO_PKG_VERSION")), "{said:?}");
+}
+
+#[test]
+fn the_same_schema_comes_out_byte_identical_every_time() {
+    assert_eq!(run(&["schema", "all"]).stdout, run(&["schema", "all"]).stdout);
+}