test: loop over aliases to asser -Zhelp output

Author: weihanglo

tests/testsuite/help.rs

@@ -158,51 +158,11 @@ fn help_alias() {
 
 #[cargo_test]
 fn alias_z_flag_help() {
-    cargo_process("build -Z help")
-        .with_stdout_contains(
-            "    -Z allow-features[..]  Allow *only* the listed unstable features",
-        )
-        .run();
-
-    cargo_process("run -Z help")
-        .with_stdout_contains(
-            "    -Z allow-features[..]  Allow *only* the listed unstable features",
-        )
-        .run();
-
-    cargo_process("check -Z help")
-        .with_stdout_contains(
-            "    -Z allow-features[..]  Allow *only* the listed unstable features",
-        )
-        .run();
-
-    cargo_process("test -Z help")
-        .with_stdout_contains(
-            "    -Z allow-features[..]  Allow *only* the listed unstable features",
-        )
-        .run();
-
-    cargo_process("b -Z help")
-        .with_stdout_contains(
-            "    -Z allow-features[..]  Allow *only* the listed unstable features",
-        )
-        .run();
-
-    cargo_process("r -Z help")
-        .with_stdout_contains(
-            "    -Z allow-features[..]  Allow *only* the listed unstable features",
-        )
-        .run();
-
-    cargo_process("c -Z help")
-        .with_stdout_contains(
-            "    -Z allow-features[..]  Allow *only* the listed unstable features",
-        )
-        .run();
-
-    cargo_process("t -Z help")
-        .with_stdout_contains(
-            "    -Z allow-features[..]  Allow *only* the listed unstable features",
-        )
-        .run();
+    for cmd in ["build", "run", "check", "test", "b", "r", "c", "t"] {
+        cargo_process(&format!("{cmd} -Z help"))
+            .with_stdout_contains(
+                "    -Z allow-features[..]  Allow *only* the listed unstable features",
+            )
+            .run();
+    }
 }