diff --git a/api/server/src/test/java/org/softwareheritage/graph/EdgesTest.java b/api/server/src/test/java/org/softwareheritage/graph/EdgesTest.java
new file mode 100644
index 0000000..72d2342
--- /dev/null
+++ b/api/server/src/test/java/org/softwareheritage/graph/EdgesTest.java
@@ -0,0 +1,112 @@
+package org.softwareheritage.graph;
+
+import java.util.ArrayList;
+
+import org.junit.Test;
+import static org.junit.Assert.assertTrue;
+
+import org.softwareheritage.graph.Edges;
+import org.softwareheritage.graph.Node;
+
+public class EdgesTest {
+  class EdgeType {
+    Node.Type src;
+    Node.Type dst;
+
+    public EdgeType(Node.Type src, Node.Type dst) {
+      this.src = src;
+      this.dst = dst;
+    }
+
+    @Override
+    public boolean equals(Object otherObj) {
+      if (otherObj == this) return true;
+      if (!(otherObj instanceof EdgeType)) return false;
+
+      EdgeType other = (EdgeType) otherObj;
+      return src == other.src && dst == other.dst;
+    }
+  }
+
+  void assertEdgeRestriction(Edges edges, ArrayList<EdgeType> expectedAllowed) {
+    Node.Type[] nodeTypes = Node.Type.values();
+    for (Node.Type src : nodeTypes) {
+      for (Node.Type dst : nodeTypes) {
+        EdgeType edge = new EdgeType(src, dst);
+        boolean isAllowed = edges.isAllowed(src, dst);
+        boolean isExpected = false;
+        for (EdgeType expected : expectedAllowed) {
+          if (expected.equals(edge)) {
+            isExpected = true;
+            break;
+          }
+        }
+
+        assertTrue("Edge type: " + src + " -> " + dst, isAllowed == isExpected);
+      }
+    }
+  }
+
+  @Test
+  public void dirToDirDirToCntEdges() {
+    Edges edges = new Edges("dir:dir,dir:cnt");
+    ArrayList<EdgeType> expected = new ArrayList<>();
+    expected.add(new EdgeType(Node.Type.DIR, Node.Type.DIR));
+    expected.add(new EdgeType(Node.Type.DIR, Node.Type.CNT));
+    assertEdgeRestriction(edges, expected);
+  }
+
+  @Test
+  public void relToRevRevToRevRevToDirEdges() {
+    Edges edges = new Edges("rel:rev,rev:rev,rev:dir");
+    ArrayList<EdgeType> expected = new ArrayList<>();
+    expected.add(new EdgeType(Node.Type.REL, Node.Type.REV));
+    expected.add(new EdgeType(Node.Type.REV, Node.Type.REV));
+    expected.add(new EdgeType(Node.Type.REV, Node.Type.DIR));
+    assertEdgeRestriction(edges, expected);
+  }
+
+  @Test
+  public void revToAllDirToDirEdges() {
+    Edges edges = new Edges("rev:*,dir:dir");
+    ArrayList<EdgeType> expected = new ArrayList<>();
+    for (Node.Type dst : Node.Type.values()) {
+      expected.add(new EdgeType(Node.Type.REV, dst));
+    }
+    expected.add(new EdgeType(Node.Type.DIR, Node.Type.DIR));
+    assertEdgeRestriction(edges, expected);
+  }
+
+  @Test
+  public void allToCntEdges() {
+    Edges edges = new Edges("*:cnt");
+    ArrayList<EdgeType> expected = new ArrayList<>();
+    for (Node.Type src : Node.Type.values()) {
+      expected.add(new EdgeType(src, Node.Type.CNT));
+    }
+    assertEdgeRestriction(edges, expected);
+  }
+
+  @Test
+  public void allEdges() {
+    Edges edges = new Edges("*:*");
+    Edges edges2 = new Edges("*");
+    ArrayList<EdgeType> expected = new ArrayList<>();
+    for (Node.Type src : Node.Type.values()) {
+      for (Node.Type dst : Node.Type.values()) {
+        expected.add(new EdgeType(src, dst));
+      }
+    }
+    assertEdgeRestriction(edges, expected);
+    assertEdgeRestriction(edges2, expected);
+  }
+
+  @Test
+  public void noEdges() {
+    Edges edges = new Edges("");
+    Edges edges2 = new Edges(null);
+    ArrayList<EdgeType> expected = new ArrayList<>();
+    assertEdgeRestriction(edges, expected);
+    assertEdgeRestriction(edges2, expected);
+  }
+}