Add lint pub_static_mut_now_immutable (#768)

* Add lint pub_static_mut_now_immutable

* Modifications in error message and description

* Modifications in description and error message

* Modifications in description and error message

* Modifications in description and error message

Author: arpity22

src/lints/pub_static_mut_now_immutable.ron

@@ -0,0 +1,50 @@
+SemverQuery(
+    id: "pub_static_mut_now_immutable",
+    human_readable_name: "pub static mut is now immutable",
+    description: "A mutable static became immutable and thus can no longer be assigned to",
+    required_update: Major,
+    reference_link: Some("https://doc.rust-lang.org/reference/items/static-items.html"),
+    query: r#"
+    {
+        CrateDiff {
+            baseline {
+                item {
+                    ... on Static {
+                        visibility_limit @filter(op: "=", value: ["$public"])
+                        mutable @filter(op: "=", value: ["$true"])
+
+                        importable_path {
+                            path @output @tag
+                            public_api @filter(op: "=", value: ["$true"])
+                        }
+                    }
+                }
+            }
+            current {
+                item {
+                    ... on Static {
+                        visibility_limit @filter(op: "=", value: ["$public"])
+                        mutable @filter(op: "!=", value: ["$true"])
+                        static_name: name @output
+
+                        importable_path {
+                            path @filter(op: "=", value: ["%path"])
+                            public_api @filter(op: "=", value: ["$true"])
+                        }
+
+                        span_: span @optional {
+                            filename @output
+                            begin_line @output
+                        }
+                    }
+                }
+            }
+        }
+    }"#,
+    arguments: {
+        "public": "public",
+        "true": true,
+    },
+    error_message: "A mutable static is now immutable and thus can no longer be assigned to",
+    per_result_error_template: Some("{{static_name}} in file {{span_filename}}:{{span_begin_line}}"),
+)

src/query.rs

@@ -516,6 +516,7 @@ add_lints!(
     pub_module_level_const_missing,
     pub_module_level_const_now_doc_hidden,
     pub_static_missing,
+    pub_static_mut_now_immutable,
     pub_static_now_doc_hidden,
     repr_c_removed,
     repr_packed_added,

test_crates/pub_static_mut_now_immutable/new/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+publish = false
+name = "pub_static_mut_now_immutable"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

test_crates/pub_static_mut_now_immutable/new/src/lib.rs

@@ -0,0 +1,25 @@
+// Basic Test cases
+pub static STATIC_A: i32 = 0;
+pub static mut STATIC_B: i32 = 0;
+static STATIC_C: i32 = 0;
+
+// Test case for #[doc(hidden)] pub static
+#[doc(hidden)]
+pub static DOC_HIDDEN_STATIC_A: i32 = 0;
+
+// Renaming or making a static #[doc(hidden)] along with making it immutable
+// should trigger only one lint
+#[doc(hidden)]
+pub static DOC_HIDDEN_STATIC_B: i32 = 0;
+pub static STATIC_RENAMED: i32 = 0;
+
+// Testing for static defined in private module
+mod PRIVATE_MODULE {
+    pub static STATIC_C: i32 = 0;
+}
+
+// Testing for static defined in #[doc(hidden)] module
+#[doc(hidden)]
+pub mod DOC_HIDDEN_MODULE {
+    pub static STATIC_C: i32 = 0;
+}

test_crates/pub_static_mut_now_immutable/old/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+publish = false
+name = "pub_static_mut_now_immutable"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

test_crates/pub_static_mut_now_immutable/old/src/lib.rs

@@ -0,0 +1,24 @@
+// Basic Test cases
+pub static mut STATIC_A: i32 = 0;
+pub static mut STATIC_B: i32 = 0;
+static mut STATIC_C: i32 = 0;
+
+// Test case for #[doc(hidden)] pub static
+#[doc(hidden)]
+pub static mut DOC_HIDDEN_STATIC_A: i32 = 0;
+
+// Renaming or making a static #[doc(hidden)] along with making it immutable
+// should trigger only one lint
+pub static mut DOC_HIDDEN_STATIC_B: i32 = 0;
+pub static mut STATIC_RENAME: i32 = 0;
+
+// Testing for static defined in private module
+mod PRIVATE_MODULE {
+    pub static mut STATIC_C: i32 = 0;
+}
+
+// Testing for static defined in #[doc(hidden)] module
+#[doc(hidden)]
+pub mod DOC_HIDDEN_MODULE {
+    pub static mut STATIC_C: i32 = 0;
+}

test_outputs/pub_static_missing.output.ron

@@ -133,4 +133,16 @@
             "visibility_limit": String("public"),
         },
     ],
+    "./test_crates/pub_static_mut_now_immutable/": [
+        {
+            "name": String("STATIC_RENAME"),
+            "path": List([
+                String("pub_static_mut_now_immutable"),
+                String("STATIC_RENAME"),
+            ]),
+            "span_begin_line": Uint64(13),
+            "span_filename": String("src/lib.rs"),
+            "visibility_limit": String("public"),
+        },
+    ],
 }

test_outputs/pub_static_mut_now_immutable.output.ron

@@ -0,0 +1,13 @@
+{
+    "./test_crates/pub_static_mut_now_immutable/": [
+        {
+            "path": List([
+                String("pub_static_mut_now_immutable"),
+                String("STATIC_A"),
+            ]),
+            "span_begin_line": Uint64(2),
+            "span_filename": String("src/lib.rs"),
+            "static_name": String("STATIC_A"),
+        },
+    ],
+}

test_outputs/pub_static_now_doc_hidden.output.ron

@@ -1,4 +1,15 @@
 {
+    "./test_crates/pub_static_mut_now_immutable/": [
+        {
+            "path": List([
+                String("pub_static_mut_now_immutable"),
+                String("DOC_HIDDEN_STATIC_B"),
+            ]),
+            "span_begin_line": Uint64(13),
+            "span_filename": String("src/lib.rs"),
+            "static_name": String("DOC_HIDDEN_STATIC_B"),
+        },
+    ],
      "./test_crates/pub_static_now_doc_hidden/": [
         {
             "path": List([