Auto merge of #13245 - linyihai:publish-public-in-test, r=epage

test: support publish package with a `public` field.

### What does this PR try to resolve?

This PR add a `public` alike method to support add a dependency as public/private,
```
Package::new("foo", "0.1.0")
        .cargo_feature("public-dependency").add_dep(Dependency::new("bar", "0.1.0").public(true))
```

and then get it from registry in test.

This PR was seperated from the #13183.

### How should we test and review this PR?
You can review on per commit.

After running the test case `publish_package_with_public_dependency`,  you can check a "public" field in `./target/tmp/cit/t0/registry/3/b/bar`.

### Additional information
r? epage

Author: bors

crates/cargo-test-support/src/registry.rs

@@ -558,6 +558,7 @@ pub struct Dependency {
     package: Option<String>,
     optional: bool,
     default_features: bool,
+    public: bool,
 }
 
 /// Entry with data that corresponds to [`tar::EntryType`].
@@ -1428,6 +1429,7 @@ impl Package {
                     "kind": dep.kind,
                     "registry": registry_url,
                     "package": dep.package,
+                    "public": dep.public,
                 })
             })
             .collect::<Vec<_>>();
@@ -1678,6 +1680,7 @@ impl Dependency {
             optional: false,
             registry: None,
             default_features: true,
+            public: false,
         }
     }
 
@@ -1731,6 +1734,12 @@ impl Dependency {
         self
     }
 
+    /// Changes this to an public dependency.
+    pub fn public(&mut self, public: bool) -> &mut Self {
+        self.public = public;
+        self
+    }
+
     /// Adds `default-features = false` if the argument is `false`.
     pub fn default_features(&mut self, default_features: bool) -> &mut Self {
         self.default_features = default_features;

tests/testsuite/pub_priv.rs

@@ -1,7 +1,7 @@
 //! Tests for public/private dependencies.
 
 use cargo_test_support::project;
-use cargo_test_support::registry::Package;
+use cargo_test_support::registry::{Dependency, Package};
 
 #[cargo_test(nightly, reason = "exported_private_dependencies lint is unstable")]
 fn exported_priv_warning() {
@@ -479,3 +479,58 @@ fn allow_priv_in_custom_build() {
         )
         .run()
 }
+
+#[cargo_test(nightly, reason = "exported_private_dependencies lint is unstable")]
+fn publish_package_with_public_dependency() {
+    Package::new("pub_bar", "0.1.0")
+        .file("src/lib.rs", "pub struct FromPub;")
+        .publish();
+    Package::new("bar", "0.1.0")
+        .cargo_feature("public-dependency")
+        .add_dep(Dependency::new("pub_bar", "0.1.0").public(true))
+        .file(
+            "src/lib.rs",
+            "
+            extern crate pub_bar;
+            pub use pub_bar::FromPub as BarFromPub;
+        ",
+        )
+        .publish();
+
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+            cargo-features = ["public-dependency"]
+            [package]
+            name = "foo"
+            version = "0.0.1"
+            [dependencies]
+            bar = {version = "0.1.0", public = true}
+        "#,
+        )
+        .file(
+            "src/lib.rs",
+            "
+            extern crate bar;
+            pub fn use_pub(_: bar::BarFromPub) {}
+        ",
+        )
+        .build();
+
+    p.cargo("check --message-format=short")
+        .masquerade_as_nightly_cargo(&["public-dependency"])
+        .with_stderr(
+            "\
+[UPDATING] `[..]` index
+[DOWNLOADING] crates ...
+[DOWNLOADED] pub_bar v0.1.0 ([..])
+[DOWNLOADED] bar v0.1.0 ([..])
+[CHECKING] pub_bar v0.1.0
+[CHECKING] bar v0.1.0
+[CHECKING] foo v0.0.1 ([..])
+[FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
+",
+        )
+        .run()
+}