Allow multiple dependencies on the same module

Allow adding multiple dependencies on the same module.  Adds a flag
to Context.walkDeps to determine whether dependencies should be
visited multiple times, and clarifies the behavior of
VisitDepsDepthFirst (continues to visit each module once, even if
there are multiple dependencies on it) and VisitDirectDeps (may
visit a module multiple times).

Test: TestWalkDepsDuplicates, TestVisit
Change-Id: I58afbe90490aca102d242d63e185386e1fe55d73

1 files changed, 92 insertions, 3 deletions

diff --git a/context_test.go b/context_test.go
index 635f73e..c08b0b7 100644
--- a/context_test.go
+++ b/context_test.go
@@ -189,7 +189,7 @@ func TestWalkDeps(t *testing.T) {
 	var outputDown string
 	var outputUp string
 	topModule := ctx.modulesFromName("A", nil)[0]
-	ctx.walkDeps(topModule,
+	ctx.walkDeps(topModule, false,
 		func(dep depInfo, parent *moduleInfo) bool {
 			if dep.module.logicModule.(Walker).Walk() {
 				outputDown += ctx.ModuleName(dep.module.logicModule)
@@ -203,10 +203,99 @@ func TestWalkDeps(t *testing.T) {
 			}
 		})
 	if outputDown != "CFG" {
-		t.Fatalf("unexpected walkDeps behaviour: %s\ndown should be: CFG", outputDown)
+		t.Errorf("unexpected walkDeps behaviour: %s\ndown should be: CFG", outputDown)
 	}
 	if outputUp != "GFC" {
-		t.Fatalf("unexpected walkDeps behaviour: %s\nup should be: GFC", outputUp)
+		t.Errorf("unexpected walkDeps behaviour: %s\nup should be: GFC", outputUp)
+	}
+}
+
+// |---B===D       - represents a non-walkable edge
+// A               = represents a walkable edge
+// |===C===E===\
+//     |       |   A should not be visited because it's the root node.
+//     |===F===G   B, D should not be walked.
+//         \===/   G should be visited multiple times
+func TestWalkDepsDuplicates(t *testing.T) {
+	ctx := NewContext()
+	ctx.MockFileSystem(map[string][]byte{
+		"Blueprints": []byte(`
+			foo_module {
+			    name: "A",
+			    deps: ["B", "C"],
+			}
+
+			bar_module {
+			    name: "B",
+			    deps: ["D"],
+			}
+
+			foo_module {
+			    name: "C",
+			    deps: ["E", "F"],
+			}
+
+			foo_module {
+			    name: "D",
+			}
+
+			foo_module {
+			    name: "E",
+			    deps: ["G"],
+			}
+
+			foo_module {
+			    name: "F",
+			    deps: ["G", "G"],
+			}
+
+			foo_module {
+			    name: "G",
+			}
+		`),
+	})
+
+	ctx.RegisterModuleType("foo_module", newFooModule)
+	ctx.RegisterModuleType("bar_module", newBarModule)
+	_, errs := ctx.ParseBlueprintsFiles("Blueprints")
+	if len(errs) > 0 {
+		t.Errorf("unexpected parse errors:")
+		for _, err := range errs {
+			t.Errorf("  %s", err)
+		}
+		t.FailNow()
+	}
+
+	_, errs = ctx.ResolveDependencies(nil)
+	if len(errs) > 0 {
+		t.Errorf("unexpected dep errors:")
+		for _, err := range errs {
+			t.Errorf("  %s", err)
+		}
+		t.FailNow()
+	}
+
+	var outputDown string
+	var outputUp string
+	topModule := ctx.modulesFromName("A", nil)[0]
+	ctx.walkDeps(topModule, true,
+		func(dep depInfo, parent *moduleInfo) bool {
+			if dep.module.logicModule.(Walker).Walk() {
+				outputDown += ctx.ModuleName(dep.module.logicModule)
+				return true
+			}
+			return false
+		},
+		func(dep depInfo, parent *moduleInfo) {
+			if dep.module.logicModule.(Walker).Walk() {
+				outputUp += ctx.ModuleName(dep.module.logicModule)
+			}
+		})
+	if outputDown != "CEGFGG" {
+		t.Errorf("unexpected walkDeps behaviour: %s\ndown should be: CEGFGG", outputDown)
+	}
+	if outputUp != "GEGGFC" {
+		t.Errorf("unexpected walkDeps behaviour: %s\nup should be: GEGGFC", outputUp)
 	}
 }