code generation: remove redundant switch cases branches in generated …

…JS (#1295) * Fix redundant branches in generated switch body, fixes #6671 (#6672) * Fix redundant branches in generated switch body, fixes #6671 Signed-Off-By: Vincenzo Pellegrini <[email protected]> * Updated changelog --------- Signed-off-by: Vincenzo Pellegrini <[email protected]> * fmt * snapshot runtime tests * chore: add changelog entry --------- Signed-off-by: Vincenzo Pellegrini <[email protected]> Co-authored-by: Vincenzo Pellegrini <[email protected]>
melange-re · Jan 14, 2025 · 9669dc8 · 9669dc8
1 parent 94a1fd6
commit 9669dc8
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Showing 11 changed files with 17 additions and 77 deletions.
diff --git a/Changes.md b/Changes.md
@@ -84,15 +84,17 @@ Unreleased
 - BREAKING: ppx: print the `deprecated` alert for `@@deriving abstract` at the
   declaration site rather than at (all) usages
   ([#1269](https://github.com/melange-re/melange/pull/1269))
-- core: prettify melange code generation for `for` loops
+- JS generation: prettify `for` loops
   ([#1275](https://github.com/melange-re/melange/pull/1275))
-- core: improve generated code formatting for `throw` and `return` statements,
-  JS objects ([#1286](https://github.com/melange-re/melange/pull/1286),
+- JS generation: improve formatting for `throw` and `return` statements, JS
+  objects ([#1286](https://github.com/melange-re/melange/pull/1286),
   [#1289](https://github.com/melange-re/melange/pull/1289))
-- core: improve generated code formatting for empty return and continue
-  statements ([#1288](https://github.com/melange-re/melange/pull/1288))
-- core: in generated code, remove trailing spaces before commas in `export`
+- JS generation: improve formatting for empty return and continue statements
+  ([#1288](https://github.com/melange-re/melange/pull/1288))
+- JS generation: remove trailing spaces before commas in `export`
   ([#1287](https://github.com/melange-re/melange/pull/1287))
+- JS generation: remove redundant switch cases branches
+  ([#1295](https://github.com/melange-re/melange/pull/1295))
 
 4.0.1 2024-06-07
 ---------------

diff --git a/jscomp/core/lam_compile.ml b/jscomp/core/lam_compile.ml
@@ -598,6 +598,15 @@ and compile_general_cases :
              break still should not be printed (it will be continuned)
          TOOD: disabled temporarily since it's not perfect yet *)
       morph_declare_to_assign cxt (fun cxt declaration ->
+          (* Exclude cases that are the same as the default if the default is defined *)
+          let cases =
+            match default with
+            | Default lam ->
+                List.filter
+                  ~f:(fun (_, lam1) -> not (Lam.eq_approx lam lam1))
+                  cases
+            | _ -> cases
+          in
           let default =
             match default with
             | Complete -> None

diff --git a/jscomp/test/dist/jscomp/test/flow_parser_reg_test.js b/jscomp/test/dist/jscomp/test/flow_parser_reg_test.js
diff --git a/jscomp/test/dist/jscomp/test/gpr_1438.js b/jscomp/test/dist/jscomp/test/gpr_1438.js
diff --git a/jscomp/test/dist/jscomp/test/gpr_1698_test.js b/jscomp/test/dist/jscomp/test/gpr_1698_test.js
diff --git a/jscomp/test/dist/jscomp/test/mario_game.js b/jscomp/test/dist/jscomp/test/mario_game.js
diff --git a/jscomp/test/dist/jscomp/test/ocaml_re_test.js b/jscomp/test/dist/jscomp/test/ocaml_re_test.js
diff --git a/jscomp/test/dist/jscomp/test/ocaml_typedtree_test.js b/jscomp/test/dist/jscomp/test/ocaml_typedtree_test.js
diff --git a/jscomp/test/dist/jscomp/test/string_test.js b/jscomp/test/dist/jscomp/test/string_test.js
diff --git a/jscomp/test/dist/jscomp/test/tscanf_test.js b/jscomp/test/dist/jscomp/test/tscanf_test.js
diff --git a/jscomp/test/dist/jscomp/test/typeof_test.js b/jscomp/test/dist/jscomp/test/typeof_test.js