Add tests for cargo add's rust-version behavior

tests/testsuite/cargo_add/mod.rs

@@ -102,6 +102,8 @@ mod quiet;
 mod registry;
 mod rename;
 mod require_weak;
+mod rust_version;
+mod rust_version_incompatible;
 mod sorted_table_with_dotted_item;
 mod target;
 mod target_cfg;
@@ -201,4 +203,14 @@ fn add_registry_packages(alt: bool) {
         .feature("eyes", &[])
         .feature("ears", &[])
         .publish();
+
+    // rust-version
+    cargo_test_support::registry::Package::new("rust-version-user", "0.1.0")
+        .alternative(alt)
+        .rust_version("1.66")
+        .publish();
+    cargo_test_support::registry::Package::new("rust-version-user", "0.2.1")
+        .alternative(alt)
+        .rust_version("1.72")
+        .publish();
 }

tests/testsuite/cargo_add/rust_version/in/Cargo.toml

@@ -0,0 +1,6 @@
+[workspace]
+
+[package]
+name = "cargo-list-test-fixture"
+version = "0.0.0"
+rust-version = "1.70"

tests/testsuite/cargo_add/rust_version/mod.rs

@@ -0,0 +1,27 @@
+use cargo_test_support::compare::assert_ui;
+use cargo_test_support::prelude::*;
+use cargo_test_support::Project;
+
+use crate::cargo_add::init_registry;
+use cargo_test_support::curr_dir;
+
+#[cargo_test(nightly, reason = "-Zmsrv-policy is unstable")]
+fn case() {
+    init_registry();
+    let project = Project::from_template(curr_dir!().join("in"));
+    let project_root = project.root();
+    let cwd = &project_root;
+
+    snapbox::cmd::Command::cargo_ui()
+        .arg("-Zmsrv-policy")
+        .arg("add")
+        .arg_line("rust-version-user")
+        .current_dir(cwd)
+        .masquerade_as_nightly_cargo(&["msrv-policy"])
+        .assert()
+        .success()
+        .stdout_matches_path(curr_dir!().join("stdout.log"))
+        .stderr_matches_path(curr_dir!().join("stderr.log"));
+
+    assert_ui().subset_matches(curr_dir!().join("out"), &project_root);
+}

tests/testsuite/cargo_add/rust_version/out/Cargo.toml

@@ -0,0 +1,9 @@
+[workspace]
+
+[package]
+name = "cargo-list-test-fixture"
+version = "0.0.0"
+rust-version = "1.70"
+
+[dependencies]
+rust-version-user = "0.1.0"

tests/testsuite/cargo_add/rust_version/stderr.log

@@ -0,0 +1,3 @@
+    Updating `dummy-registry` index
+warning: selecting older version of `rust-version-user` to satisfy the minimum supported rust version
+      Adding rust-version-user v0.1.0 to dependencies.

tests/testsuite/cargo_add/rust_version_incompatible/in/Cargo.toml

@@ -0,0 +1,6 @@
+[workspace]
+
+[package]
+name = "cargo-list-test-fixture"
+version = "0.0.0"
+rust-version = "1.56"

tests/testsuite/cargo_add/rust_version_incompatible/mod.rs

@@ -0,0 +1,27 @@
+use cargo_test_support::compare::assert_ui;
+use cargo_test_support::prelude::*;
+use cargo_test_support::Project;
+
+use crate::cargo_add::init_registry;
+use cargo_test_support::curr_dir;
+
+#[cargo_test(nightly, reason = "-Zmsrv-policy is unstable")]
+fn case() {
+    init_registry();
+    let project = Project::from_template(curr_dir!().join("in"));
+    let project_root = project.root();
+    let cwd = &project_root;
+
+    snapbox::cmd::Command::cargo_ui()
+        .arg("-Zmsrv-policy")
+        .arg("add")
+        .arg_line("rust-version-user")
+        .current_dir(cwd)
+        .masquerade_as_nightly_cargo(&["msrv-policy"])
+        .assert()
+        .failure()
+        .stdout_matches_path(curr_dir!().join("stdout.log"))
+        .stderr_matches_path(curr_dir!().join("stderr.log"));
+
+    assert_ui().subset_matches(curr_dir!().join("out"), &project_root);
+}

tests/testsuite/cargo_add/rust_version_incompatible/out/Cargo.toml

@@ -0,0 +1,6 @@
+[workspace]
+
+[package]
+name = "cargo-list-test-fixture"
+version = "0.0.0"
+rust-version = "1.56"

tests/testsuite/cargo_add/rust_version_incompatible/stderr.log

@@ -0,0 +1,2 @@
+    Updating `dummy-registry` index
+error: could not find version of crate `rust-version-user` that satisfies the minimum supported rust version