Add regression test for sharkdp#570

numbat-cli/Cargo.toml

@@ -29,6 +29,7 @@ version = "4"
 features = ["suggestions", "color", "wrap_help", "derive"]
 
 [dev-dependencies]
+insta = { version = "1.34", features = ["filters"] }
 insta-cmd = "0.6"
 
 [[bin]]

numbat-cli/tests/integration.rs

@@ -295,3 +295,36 @@ fn info_text() {
     ----- stderr -----
     "###);
 }
+
+#[test]
+fn identifier_clash_errors() {
+    // https://github.com/sharkdp/numbat/issues/570
+
+    let expr = "@aliases(malaysian_ringgits, MYR: short, myr, RM, rm) \n\
+                unit malaysian_ringgit: Money = 1.234 EUR";
+
+    insta::with_settings!({filters => vec![
+        (r"\bFile .*:[0-9]+:[0-9]+\b", "[redacted path]"), // redact absolute file system paths
+        (r"[ 0-9][0-9] │", "XX │"), // redact line numbers so we don't have to change this all the time
+    ]}, {
+        assert_cmd_snapshot!(numbat().arg("--expression").arg(expr), @r###"
+        success: false
+        exit_code: 1
+        ----- stdout -----
+
+        ----- stderr -----
+        error: identifier clash in definition
+           ┌─ Module 'units::time', [redacted path]
+           │
+        XX │ unit year: Time = 365.242_188_1 days
+           │      ---- Previously defined here
+           │
+           ┌─ <input:1>:1:42
+           │
+        XX │ @aliases(malaysian_ringgits, MYR: short, myr, RM, rm) 
+           │                                          ^^^ identifier is already in use
+
+        Interpreter stopped
+        "###);
+    });
+}