fix: Issue/604 (#717)

* fix: Issue/604

* docs: update CHANGELOG.md

* chore: revert line

* fix: code style

* fix: code style

* docs: Update CHANGELOG.md

---------

Co-authored-by: Jakub Bednář <[email protected]>

Author: KYankee6

CHANGELOG.md

@@ -5,6 +5,7 @@
 1. [#684](https://github.com/influxdata/influxdb-client-java/issues/684): Fix checking for CSV end of table marker when parsing CSV stream to InfluxQLQueryResult, needed for example when parsing the results of a query like "SHOW SERIES".
 2. [#662](https://github.com/influxdata/influxdb-client-java/issues/662): Adds to FluxDsl support for the `|> elapsed(unit)` function.
 3. [#623](https://github.com/influxdata/influxdb-client-java/issues/623): Enables the use of IPv6 addresses. 
+4. [#604](https://github.com/influxdata/influxdb-client-java/issues/604): Custom FluxDSL restrictions for regular expressions
 
 ### Dependencies
 

flux-dsl/src/main/java/com/influxdb/query/dsl/functions/restriction/ColumnRestriction.java

@@ -192,7 +192,11 @@ public String toString() {
 
             String value;
             if (fieldValue instanceof String) {
-                value = "\"" + escapeDoubleQuotes((String) fieldValue) + "\"";
+                if (operator.contains("~")) {
+                    value = escapeDoubleQuotes((String) fieldValue);
+                } else {
+                    value = "\"" + escapeDoubleQuotes((String) fieldValue) + "\"";
+                }
             } else {
                 value = FunctionsParameters.serializeValue(fieldValue, false);
             }

flux-dsl/src/test/java/com/influxdb/query/dsl/functions/restriction/RestrictionsTest.java

@@ -74,6 +74,17 @@ void contains() {
         Assertions.assertThat(restrictions.toString()).isEqualTo("contains(value: r[\"_value\"], set:[\"value1\", \"value2\"])");
     }
 
+    @Test
+    void custom (){
+        Restrictions restrictions = Restrictions.value().custom("/.*target.*/", "=~");
+
+        Assertions.assertThat(restrictions.toString()).isEqualTo("r[\"_value\"] =~ /.*target.*/");
+
+        restrictions = Restrictions.value().custom("1", "==");
+
+        Assertions.assertThat(restrictions.toString()).isEqualTo("r[\"_value\"] == \"1\"");
+    }
+
     @Test
     void not() {