fix(eager execution): Fix bug from escaped slash right before quote character

Author: jasmith-hs

src/main/java/com/hubspot/jinjava/util/EagerExpressionResolver.java

@@ -175,7 +175,12 @@ public static Set<String> findDeferredWords(
           );
           prevQuotePos = curPos;
         }
-        prevChar = c;
+        if (prevChar == '\\') {
+          // Double escapes cancel out.
+          prevChar = 0;
+        } else {
+          prevChar = c;
+        }
         curPos++;
       }
       words.addAll(

src/test/java/com/hubspot/jinjava/util/EagerExpressionResolverTest.java

@@ -357,6 +357,15 @@ public void itHandlesSingleQuotes() {
       .isEqualTo("' & ' & '\"");
   }
 
+  @Test
+  public void itHandlesEscapedSlashBeforeQuoteProperly() {
+    EagerExpressionResult eagerExpressionResult = eagerResolveExpression(
+      "deferred|replace('\\\\', '.')"
+    );
+    assertThat(eagerExpressionResult.getDeferredWords())
+      .containsExactlyInAnyOrder("deferred", "replace.filter");
+  }
+
   @Test
   public void itHandlesNewlines() {
     context.put("foo", "\n");