From cb66e7065325e1117371e6aad1cd7955088dd33d Mon Sep 17 00:00:00 2001
From: Udo Klimaschewski <udo.klimaschewski@gmx.net>
Date: Tue, 25 May 2021 11:00:26 +0200
Subject: [PATCH] String variable was not recognized when passed as a param
 (#258)

Co-authored-by: Fanime Fartoon <useless.anime@gmail.com>
---
 .../java/com/udojava/evalex/Expression.java   |  3 +-
 .../java/com/udojava/evalex/TestCustoms.java  | 37 ++++++++++++++++++-
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/udojava/evalex/Expression.java b/src/main/java/com/udojava/evalex/Expression.java
index 61f3876e..6db4cd78 100644
--- a/src/main/java/com/udojava/evalex/Expression.java
+++ b/src/main/java/com/udojava/evalex/Expression.java
@@ -1452,7 +1452,8 @@ public BigDecimal eval() {
                         }
 
                         public String getString() {
-                            return token.surface;
+                        	LazyNumber lazyVariable = variables.get(token.surface);
+                            return lazyVariable.getString();
                         }
                     });
                     break;
diff --git a/src/test/java/com/udojava/evalex/TestCustoms.java b/src/test/java/com/udojava/evalex/TestCustoms.java
index 5b0d2c0c..212ae0c5 100644
--- a/src/test/java/com/udojava/evalex/TestCustoms.java
+++ b/src/test/java/com/udojava/evalex/TestCustoms.java
@@ -229,4 +229,39 @@ public BigDecimal eval(BigDecimal v1, BigDecimal v2) {
 
         assertEquals("1", e.eval().toPlainString());
     }
-}
+
+    @Test
+    public void testCustomFunctionWithStringParams() {
+        Expression e = new Expression("INDEXOF(STRING1, STRING2)");
+        e.addLazyFunction(new AbstractLazyFunction("INDEXOF", 2) {
+            @Override
+            public LazyNumber lazyEval(List<LazyNumber> lazyParams) {
+                String st1 = lazyParams.get(0).getString();
+                String st2 = lazyParams.get(1).getString();
+                final int index = st1.indexOf(st2);
+
+                return new LazyNumber() {
+                    @Override
+                    public BigDecimal eval() {
+                        return new BigDecimal(index);
+                    }
+
+                    @Override
+                    public String getString() {
+                        return Integer.toString(index);
+                    }
+                };
+            }
+        });
+
+        e.setVariable("STRING1", "The quick brown fox");
+        e.setVariable("STRING2", "The");
+
+        assertEquals("0", e.eval().toPlainString());
+
+        e.setVariable("STRING1", "The quick brown fox");
+        e.setVariable("STRING2", "brown");
+
+        assertEquals("10", e.eval().toPlainString());
+    }
+}