feat(flux-dsl): supports empty logic operator (#213)

bednar · web-flow · commit 5be7b5fb5d40 · 2021-04-07T07:13:44.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -9,6 +9,7 @@ You have to replace your dependency from: `influxdb-client-scala` to:
 
 ### Features
 1. [#211](https://github.com/influxdata/influxdb-client-java/pull/211): Add supports for Scala cross versioning [`2.12`, `2.13`]
+1. [#213](https://github.com/influxdata/influxdb-client-java/pull/213): Supports empty logic operator [FluxDSL]
 
 ## 2.1.0 [2021-04-01]
 
diff --git a/flux-dsl/src/main/java/com/influxdb/query/dsl/functions/restriction/Restrictions.java b/flux-dsl/src/main/java/com/influxdb/query/dsl/functions/restriction/Restrictions.java
@@ -21,7 +21,7 @@
  */
 package com.influxdb.query.dsl.functions.restriction;
 
-import java.util.stream.Collectors;
+import java.util.StringJoiner;
 import java.util.stream.Stream;
 import javax.annotation.Nonnull;
 
@@ -141,7 +141,12 @@ public String toString() {
 
             return Stream.of(restrictions)
                     .map(Object::toString)
-                    .collect(Collectors.joining(" " + operator + " ", "(", ")"));
+                    .filter(it -> it != null && !it.isEmpty())
+                    .collect(() -> new StringJoiner(" " + operator + " ", "(", ")")
+                                    .setEmptyValue(""),
+                            StringJoiner::add,
+                            StringJoiner::merge)
+                    .toString();
         }
     }
 }
diff --git a/flux-dsl/src/test/java/com/influxdb/query/dsl/functions/restriction/RestrictionsTest.java b/flux-dsl/src/test/java/com/influxdb/query/dsl/functions/restriction/RestrictionsTest.java
@@ -63,4 +63,21 @@ void exists() {
 
         Assertions.assertThat(restrictions.toString()).isEqualTo("exists r[\"_value\"]");
     }
+
+    @Test
+    void emptyLogical() {
+
+        Restrictions restrictions = Restrictions.and(
+                Restrictions.tag("tag").equal("production"),
+                Restrictions.or(),
+                Restrictions.measurement().equal("data")
+        );
+        Assertions.assertThat(restrictions.toString()).isEqualTo("(r[\"tag\"] == \"production\" and r[\"_measurement\"] == \"data\")");
+
+        restrictions = Restrictions.and(Restrictions.or());
+        Assertions.assertThat(restrictions.toString()).isEqualTo("");
+
+        restrictions = Restrictions.or(Restrictions.or());
+        Assertions.assertThat(restrictions.toString()).isEqualTo("");
+    }
 }

Original file line number	Diff line number	Diff line change
`@@ -21,7 +21,7 @@`
`21`	`21`	`*/`
`22`	`22`	`package com.influxdb.query.dsl.functions.restriction;`
`23`	`23`
`24`		`-import java.util.stream.Collectors;`
	`24`	`+import java.util.StringJoiner;`
`25`	`25`	`import java.util.stream.Stream;`
`26`	`26`	`import javax.annotation.Nonnull;`
`27`	`27`
`@@ -141,7 +141,12 @@ public String toString() {`
`141`	`141`
`142`	`142`	`return Stream.of(restrictions)`
`143`	`143`	`.map(Object::toString)`
`144`		`- .collect(Collectors.joining(" " + operator + " ", "(", ")"));`
	`144`	`+ .filter(it -> it != null && !it.isEmpty())`
	`145`	`+ .collect(() -> new StringJoiner(" " + operator + " ", "(", ")")`
	`146`	`+ .setEmptyValue(""),`
	`147`	`+ StringJoiner::add,`
	`148`	`+ StringJoiner::merge)`
	`149`	`+ .toString();`
`145`	`150`	`}`
`146`	`151`	`}`
`147`	`152`	`}`