Add tests to cover new mutations in cargo-mutants

Author: zaneduffield

src/fnvalue.rs

@@ -202,9 +202,6 @@ fn type_replacements(type_: &Type, error_exprs: &[Expr]) -> impl Iterator<Item =
                     .collect_vec()
             }
         },
-        Type::Tuple(TypeTuple { elems, .. }) if elems.is_empty() => {
-            vec![quote! { () }]
-        }
         Type::Tuple(TypeTuple { elems, .. }) => {
             // Generate the cartesian product of replacements of every type within the tuple.
             elems

src/workspace.rs

@@ -201,10 +201,6 @@ impl Workspace {
         // in that case we'll just fall back to everything, for lack of a better option.
         // TODO: Use the new cargo_metadata API that doesn't panic?
         match catch_unwind(|| metadata.workspace_default_packages()) {
-            Ok(default_packages) if default_packages.is_empty() => {
-                debug!("manifest has no explicit default packages");
-                PackageSelection::All
-            }
             Ok(default_packages) => {
                 let default_package_names: Vec<&str> = default_packages
                     .iter()

testdata/many_patterns/src/binops.rs

@@ -6,6 +6,14 @@ pub fn binops() {
     a -= 2;
     a *= 3;
     a /= 2;
+
+    let mut b;
+    b = a < 0;
+    b = a <= 0;
+    b = a > 0;
+    b = a >= 0;
+    b = a == 0;
+    b = a != 0;
 }
 
 pub fn bin_assign() -> i32 {
@@ -15,5 +23,6 @@ pub fn bin_assign() -> i32 {
     a &= 0x0f;
     a >>= 4;
     a <<= 1;
+    a %= 1;
     a
 }

testdata/workspace_default_members/Cargo_test.toml

@@ -0,0 +1,6 @@
+# This workspace has default-members set, which influences which packages are mutated by default.
+
+[workspace]
+members = ["main", "excluded"]
+default-members = ["main"]
+resolver = "2"

testdata/workspace_default_members/excluded/Cargo_test.toml

@@ -0,0 +1,10 @@
+[package]
+name = "excluded"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+mutants = "0.0.3"

testdata/workspace_default_members/excluded/src/main.rs

@@ -0,0 +1,3 @@
+fn main() -> i32 {
+    100
+}

testdata/workspace_default_members/main/Cargo_test.toml

@@ -0,0 +1,10 @@
+[package]
+name = "main"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+mutants = "0.0.3"

testdata/workspace_default_members/main/src/main.rs

@@ -0,0 +1,6 @@
+const X: u32 = 2 + 1;
+
+#[test]
+fn test() {
+    assert_eq!(X, 3);
+}

tests/main.rs

@@ -45,6 +45,18 @@ fn show_version() {
         .stdout(predicates::str::is_match(r"^cargo-mutants \d+\.\d+\.\d+(-.*)?\n$").unwrap());
 }
 
+#[test]
+fn show_help() {
+    // Asserting on the entire help message would be a bit too annoying to maintain.
+    run()
+        .args(["mutants", "--help"])
+        .assert()
+        .success()
+        .stdout(predicates::str::contains(
+            "Usage: cargo mutants [OPTIONS] [-- <CARGO_TEST_ARGS>...]",
+        ));
+}
+
 #[test]
 fn uses_cargo_env_var_to_run_cargo_so_invalid_value_fails() {
     let tmp_src_dir = copy_of_testdata("well_tested");