Support unit tests for jsondoclint

Author: aDotInTheVoid

src/bootstrap/builder.rs

@@ -644,6 +644,7 @@ impl<'a> Builder<'a> {
                 test::CrateLibrustc,
                 test::CrateRustdoc,
                 test::CrateRustdocJsonTypes,
+                test::CrateJsonDocLint,
                 test::Linkcheck,
                 test::TierCheck,
                 test::ReplacePlaceholderTest,

src/bootstrap/test.rs

@@ -90,6 +90,42 @@ fn try_run_quiet(builder: &Builder<'_>, cmd: &mut Command) -> bool {
     true
 }
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub struct CrateJsonDocLint {
+    host: TargetSelection,
+}
+
+impl Step for CrateJsonDocLint {
+    type Output = ();
+    const ONLY_HOSTS: bool = true;
+    const DEFAULT: bool = true;
+
+    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        run.path("src/tools/jsondoclint")
+    }
+
+    fn make_run(run: RunConfig<'_>) {
+        run.builder.ensure(CrateJsonDocLint { host: run.target });
+    }
+
+    fn run(self, builder: &Builder<'_>) {
+        let bootstrap_host = builder.config.build;
+        let compiler = builder.compiler(0, bootstrap_host);
+
+        let cargo = tool::prepare_tool_cargo(
+            builder,
+            compiler,
+            Mode::ToolBootstrap,
+            bootstrap_host,
+            "test",
+            "src/tools/jsondoclint",
+            SourceType::InTree,
+            &[],
+        );
+        try_run(builder, &mut cargo.into());
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct Linkcheck {
     host: TargetSelection,

src/tools/jsondoclint/src/json_find.rs

@@ -72,3 +72,6 @@ fn find_selector_recursive(
         }
     }
 }
+
+#[cfg(test)]
+mod tests;

src/tools/jsondoclint/src/json_find/tests.rs

@@ -0,0 +1,4 @@
+#[test]
+fn should_fail() {
+    assert_eq!(true, false);
+}