test: migrate help to snapbox

tests/testsuite/help.rs

@@ -1,8 +1,7 @@
 //! Tests for cargo's help output.
 
-#![allow(deprecated)]
-
 use cargo_test_support::registry::Package;
+use cargo_test_support::str;
 use cargo_test_support::{basic_manifest, cargo_exe, cargo_process, paths, process, project};
 use std::fs;
 use std::path::Path;
@@ -16,11 +15,6 @@ fn help() {
  cargo_process("help build").run();
  cargo_process("build -h").run();
  cargo_process("help help").run();
- // Ensure that help output goes to stdout, not stderr.
- cargo_process("search --help").with_stderr("").run();
- cargo_process("search --help")
- .with_stdout_contains("[..] --frozen [..]")
- .run();
 }
 
 #[cargo_test]
@@ -41,7 +35,10 @@ fn help_external_subcommand() {
  .publish();
  cargo_process("install cargo-fake-help").run();
  cargo_process("help fake-help")
- .with_stdout("fancy help output\n")
+ .with_stdout_data(str![[r#"
+fancy help output
+
+"#]])
  .run();
 }
 
@@ -147,8 +144,17 @@ fn help_alias() {
  // The `empty-alias` returns an error.
  cargo_process("help empty-alias")
  .env("PATH", Path::new(""))
- .with_stderr_contains("[..]The subcommand 'empty-alias' wasn't recognized[..]")
- .run_expect_error();
+ .with_status(101)
+ .with_stderr_data(str![[r#"
+[ERROR] no such command: `empty-alias`
+
+ Did you mean `empty-alias`?
+
+ View all installed commands with `cargo --list`
+ Find a package to install `empty-alias` with `cargo search cargo-empty-alias`
+
+"#]])
+ .run();
 
  // Because `simple-alias` aliases a subcommand with no arguments, help shows the manpage.
  help_with_man_and_path("", "simple-alias", "build", Path::new(""));
@@ -157,14 +163,3 @@ fn help_alias() {
  let out = help_with_stdout_and_path("complex-alias", Path::new(""));
  assert_eq!(out, "`complex-alias` is aliased to `build --release`\n");
 }
-
-#[cargo_test]
-fn alias_z_flag_help() {
- 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();
- }
-}