--- a/src/layout/Layout.test.ts	Sun Mar 20 14:10:56 2022 -0700
+++ b/src/layout/Layout.test.ts	Sun Mar 20 14:12:03 2022 -0700
@@ -74,7 +74,7 @@
       const vc = new ViewConfig();
       await vc.readFromGraph(`
         @prefix : <http://example.com/> .
-  
+
         <> a :View; :table [ :primaryType :T1 ] .`);
       const layout = new Layout(vc);
       lr = layout.plan(await typedStatements());
@@ -199,7 +199,104 @@
         { rdfTypes: [EX("T1")], pred: EX("p3") },
         { rdfTypes: [EX("T2")], pred: EX("p2") },
       ]);
-    })
+    });
+    it("joins over an edge", async () => {
+      const vc = new ViewConfig();
+      await vc.readFromGraph(`
+        @prefix : <http://example.com/> .
+
+        <> a :View; :table [
+          :primaryType :T1;
+          :link   [:predicate :predLink ] ] .
+      `);
+      const layout = new Layout(vc);
+      const lr = layout.plan(
+        await n3Graph(`
+        @prefix : <http://example.com/> .
+        :g1 {
+          :a a :T1; :color :red; :predLink :b .
+          :b a :T2; :size :big .
+        }
+      `)
+      );
+
+      expect(lr.sections).toHaveLength(1); // no loose statements
+      const section0 = lr.sections[0] as AlignedTable;
+      expect(section0.rowHeaders).toEqual([EX("a")]);
+      expect(section0.columnHeaders).toEqual([
+        { rdfTypes: [EX("T1")], pred: EX("color") },
+        // :predLink column is hidden
+        { rdfTypes: [EX("T2")], pred: EX("size") },
+      ]);
+    });
   });
+  it("joins 3 subjects into one", async () => {
+    const vc = new ViewConfig();
+    await vc.readFromGraph(`
+      @prefix : <http://example.com/> .
+
+      <> a :View; :table [
+        :primaryType :T1;
+        :link
+          [:predicate :pred1Link ],
+          [:predicate :pred2Link ]
+       ] .
+    `);
+    const layout = new Layout(vc);
+    const lr = layout.plan(
+      await n3Graph(`
+      @prefix : <http://example.com/> .
+      :g1 {
+        :a a :T1; :color :red; :pred1Link :b; :pred2Link :c .
+        :b a :T2; :size :big .
+        :c a :T3; :bright 50 .
+      }
+    `)
+    );
+
+    expect(lr.sections).toHaveLength(1); // no loose statements
+    const section0 = lr.sections[0] as AlignedTable;
+    expect(section0.rowHeaders).toEqual([EX("a")]);
+    expect(section0.columnHeaders).toEqual([
+      { rdfTypes: [EX("T1")], pred: EX("color") },
+      { rdfTypes: [EX("T2")], pred: EX("size") },
+      { rdfTypes: [EX("T3")], pred: EX("bright") },
+    ]);
+  });
+  it("links rows to predicate that themselves are linked in", async () => {
+    const vc = new ViewConfig();
+    await vc.readFromGraph(`
+      @prefix : <http://example.com/> .
+
+      <> a :View; :table [
+        :primaryType :T1;
+        :link
+          [:predicate :pred1Link ],
+          [:predicate :pred2Link ]
+       ] .
+    `);
+    const layout = new Layout(vc);
+    const lr = layout.plan(
+      await n3Graph(`
+      @prefix : <http://example.com/> .
+      :g1 {
+        :a a :T1; :color :red; :pred1Link :b .
+        :b a :T2; :size :big;  :pred2Link :c .
+        :c a :T3; :bright 50 .
+      }
+    `)
+    );
+    console.log(JSON.stringify(lr.sections, null, "  "));
+
+    expect(lr.sections).toHaveLength(1); // no loose statements
+    const section0 = lr.sections[0] as AlignedTable;
+    expect(section0.rowHeaders).toEqual([EX("a")]);
+    expect(section0.columnHeaders).toEqual([
+      { rdfTypes: [EX("T1")], pred: EX("color") },
+      { rdfTypes: [EX("T2")], pred: EX("size") },
+      { rdfTypes: [EX("T3")], pred: EX("bright") },
+    ]);
+  });
+
   it.skip("makes a table out of ungrouped triples with the same type", async () => {});
 });