refactor(minifier): move tests to their src files (#5912)

crates/oxc_minifier/Cargo.toml

@@ -17,7 +17,7 @@ description.workspace = true
 workspace = true
 
 [lib]
-test = false
+test = true
 doctest = false
 
 [dependencies]

crates/oxc_minifier/src/ast_passes/collapse_variable_declarations.rs

@@ -86,3 +86,34 @@ impl<'a> CollapseVariableDeclarations {
         *stmts = new_stmts;
     }
 }
+
+/// <https://github.com/google/closure-compiler/blob/master/test/com/google/javascript/jscomp/CollapseVariableDeclarations.java>
+#[cfg(test)]
+mod test {
+    use oxc_allocator::Allocator;
+
+    use crate::{tester, CompressOptions};
+
+    fn test(source_text: &str, expected: &str) {
+        let allocator = Allocator::default();
+        let mut pass = super::CollapseVariableDeclarations::new(CompressOptions::default());
+        tester::test(&allocator, source_text, expected, &mut pass);
+    }
+
+    fn test_same(source_text: &str) {
+        test(source_text, source_text);
+    }
+
+    #[test]
+    fn cjs() {
+        // Do not join `require` calls for cjs-module-lexer.
+        test_same(
+            "
+    Object.defineProperty(exports, '__esModule', { value: true });
+    var compilerDom = require('@vue/compiler-dom');
+    var runtimeDom = require('@vue/runtime-dom');
+    var shared = require('@vue/shared');
+    ",
+        );
+    }
+}

crates/oxc_minifier/src/ast_passes/mod.rs

@@ -28,7 +28,7 @@ impl<'a> NodeUtil for TraverseCtx<'a> {
     }
 }
 
-pub trait CompressorPass<'a> {
+pub trait CompressorPass<'a>: Traverse<'a> {
     fn build(&mut self, program: &mut Program<'a>, ctx: &mut TraverseCtx<'a>)
     where
         Self: Traverse<'a>,