Fix multi-link deserialization (#28)

dbschema/migrations/00008.edgeql

@@ -0,0 +1,9 @@
+CREATE MIGRATION m1xt33ahn2zm5wiwbdubmpttdcg5ywahjme2dnpj3jx3hfhkzcc3sq
+    ONTO m1tig3qk3mnrb2xpszwyodgurkdeyza6yt67zo7kfljc2icy3e7yma
+{
+  CREATE TYPE tests::Links {
+      CREATE LINK b: tests::Links;
+      CREATE MULTI LINK c: tests::Links;
+      CREATE PROPERTY a: std::str;
+  };
+};

dbschema/migrations/00009.edgeql

@@ -0,0 +1,9 @@
+CREATE MIGRATION m1hds33s7w5uj53nhqljjf7cqpzzv64csyo7r4di4cf5f22q5ydywa
+    ONTO m1xt33ahn2zm5wiwbdubmpttdcg5ywahjme2dnpj3jx3hfhkzcc3sq
+{
+  ALTER TYPE tests::Links {
+      ALTER PROPERTY a {
+          CREATE CONSTRAINT std::exclusive;
+      };
+  };
+};

dbschema/tests.esdl

@@ -4,4 +4,12 @@ module tests {
         required property b -> str;
         required property c -> str;
     }
+
+    type Links {
+        a: str {
+            constraint exclusive;
+        };
+        b: Links;
+        multi c: Links;
+    }
 }

examples/java-examples/src/main/java/com/edgedb/examples/LinkProperties.java

@@ -1,6 +1,7 @@
 package com.edgedb.examples;
 
 import com.edgedb.driver.EdgeDBClient;
+import com.edgedb.driver.annotations.EdgeDBLinkType;
 import com.edgedb.driver.annotations.EdgeDBType;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -16,6 +17,7 @@ public static final class Person {
         public String name;
         public Long age;
         public Person bestFriend;
+        @EdgeDBLinkType(Person.class)
         public Collection<Person> friends;
     }
 

src/driver/src/main/java/com/edgedb/driver/binary/codecs/visitors/TypeVisitor.java

@@ -131,6 +131,10 @@ public static Codec<?> visitCompilableCodec(@NotNull TypeVisitor visitor, @NotNu
         // context type control:
         // inner codec:
         try(var ignored = visitor.enterNewContext(v -> {
+            if(v.isRealType) {
+                return;
+            }
+
             var innerType = TypeUtils.tryPullWrappingType(visitor.getContext().type);
 
             if(innerType == null) {

src/driver/src/test/java/QueryTests.java

@@ -1,15 +1,50 @@
 import com.edgedb.driver.EdgeDBClient;
+import com.edgedb.driver.annotations.EdgeDBLinkType;
 import com.edgedb.driver.annotations.EdgeDBType;
 import com.edgedb.driver.datatypes.MultiRange;
 import com.edgedb.driver.datatypes.Range;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.HashMap;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class QueryTests {
+    @EdgeDBType
+    public static final class Links {
+        public String a;
+        public Links b;
+        @EdgeDBLinkType(Links.class)
+        public Collection<Links> c;
+    }
+
+    @Test
+    public void testLinkProperties() throws Exception {
+        try(var client = new EdgeDBClient().withModule("tests")) {
+            var result = client
+                    .execute(
+                            "with a := (insert Links { a := 'A' } unless conflict on .a)," +
+                            "b := (insert Links { a := 'B'} unless conflict on .a)," +
+                            "c := (insert Links { a := 'C', c := b } unless conflict on .a)" +
+                            "insert Links { a := 'D', c := { a, b, c }, b := c } unless conflict on .a")
+                    .thenCompose(v ->
+                            client.queryRequiredSingle(
+                                    Links.class,
+                                    "select Links { a, c: { a, b, c }, b: { a, b, c } } filter .a = 'D'"
+                            )
+                    )
+                    .toCompletableFuture().get();
+
+            assertThat(result.a).isEqualTo("D");
+
+            for (var linkClass : result.c) {
+                assertThat(linkClass.getClass()).isEqualTo(Links.class); // verify its deserialized an actual object
+            }
+        }
+    }
+
     @Test
     public void testMultiRanges() {
         try(var client = new EdgeDBClient()) {