From bc73363afa2163e5934b6d4d7b9c41feb505ebd1 Mon Sep 17 00:00:00 2001
From: Lars Hvam <5888506+larshp@users.noreply.github.com>
Date: Tue, 7 Apr 2026 20:43:12 +0200
Subject: [PATCH] array filter()

---
 src/zcl_mjs.clas.abap             | 32 +++++++++++++++++++++++++++++++
 src/zcl_mjs.clas.testclasses.abap | 12 ++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/src/zcl_mjs.clas.abap b/src/zcl_mjs.clas.abap
index 3059041..60b34e1 100644
--- a/src/zcl_mjs.clas.abap
+++ b/src/zcl_mjs.clas.abap
@@ -2527,6 +2527,38 @@ CLASS zcl_mjs IMPLEMENTATION.
               ENDIF.
             ENDIF.
             RETURN.
+          WHEN `filter`.
+            IF lines( it_args ) > 0.
+              DATA ls_flt_cb TYPE zif_mjs=>ty_value.
+              READ TABLE it_args INDEX 1 INTO ls_flt_cb.
+              IF ls_flt_cb-type = 4 AND ls_flt_cb-fn IS BOUND.
+                DATA lo_flt_arr TYPE REF TO zcl_mjs_arr.
+                CREATE OBJECT lo_flt_arr.
+                DATA lv_flt_idx TYPE i VALUE 0.
+                LOOP AT is_obj-arr->items INTO DATA(lr_flt_item).
+                  DATA ls_flt_elem TYPE zif_mjs=>ty_value.
+                  ls_flt_elem = unbox_value( lr_flt_item ).
+                  DATA lt_flt_args TYPE zif_mjs=>tt_value_slots.
+                  CLEAR lt_flt_args.
+                  APPEND ls_flt_elem TO lt_flt_args.
+                  APPEND number_val( CONV f( lv_flt_idx ) ) TO lt_flt_args.
+                  APPEND is_obj TO lt_flt_args.
+                  DATA(ls_flt_result) = call_function(
+                    ir_fn   = ls_flt_cb-fn
+                    it_args = lt_flt_args
+                    io_env  = io_env ).
+                  IF is_true( ls_flt_result ) = abap_true.
+                    lo_flt_arr->push( lr_flt_item ).
+                  ENDIF.
+                  lv_flt_idx = lv_flt_idx + 1.
+                ENDLOOP.
+                rs_val-type = 7.
+                rs_val-arr = lo_flt_arr.
+              ENDIF.
+            ELSE.
+              rs_val = array_val( VALUE #( ) ).
+            ENDIF.
+            RETURN.
           WHEN `splice`.
             DATA lt_spl_args TYPE zif_mjs=>tt_value_slots.
             lt_spl_args = it_args.
diff --git a/src/zcl_mjs.clas.testclasses.abap b/src/zcl_mjs.clas.testclasses.abap
index 0115618..7829f1f 100644
--- a/src/zcl_mjs.clas.testclasses.abap
+++ b/src/zcl_mjs.clas.testclasses.abap
@@ -101,6 +101,7 @@ CLASS ltcl_test DEFINITION FOR TESTING
     METHODS test_set_has FOR TESTING RAISING zcx_mjs_runtime.
     METHODS test_namespace_class FOR TESTING RAISING zcx_mjs_runtime.
     METHODS test_class_typeof FOR TESTING RAISING zcx_mjs_runtime.
+    METHODS test_array_filter FOR TESTING RAISING zcx_mjs_runtime.
 
     METHODS test262 FOR TESTING RAISING zcx_mjs_runtime.
 
@@ -856,6 +857,17 @@ CLASS ltcl_test IMPLEMENTATION.
       exp = |function| ).
   ENDMETHOD.
 
+  METHOD test_array_filter.
+    DATA(lv_nl) = cl_abap_char_utilities=>newline.
+    DATA(lv_js) =
+      `const arr = [1, 2, 3, 4, 5];` && lv_nl &&
+      `const filtered = arr.filter(x => x > 2);` && lv_nl &&
+      `console.log(filtered.length);`.
+    cl_abap_unit_assert=>assert_equals(
+      act = trim( zcl_mjs=>eval( lv_js ) )
+      exp = |3| ).
+  ENDMETHOD.
+
   METHOD test262.
     DATA(lv_nl) = cl_abap_char_utilities=>newline.
     DATA(lv_js) =