weld: Filter out transitive dependencies for testing and remove dupli…

…cates (#5)

* wip

* weld: Filter our transitive dependencies for testing

* remove dereferencing

* rebase

internal/gen.go

@@ -77,7 +77,7 @@ func Generate(ctx context.Context, args Args) (*Result, error) {
 
 	var testingOut []byte
 	if args.ForTesting {
-		testingOut, err = execTestingTpl(tplData)
+		testingOut, err = execTestingTpl(tplData, specBcks)
 		if err != nil {
 			return nil, err
 		}
@@ -102,7 +102,7 @@ func Generate(ctx context.Context, args Args) (*Result, error) {
 		SpecBackends:   specBcks,
 		SelectedNodes:  selected.SelectedNodes,
 		TransBackends:  selected.TransitiveBackends,
-		TplData:        tplData,
+		TplData:        &tplData,
 		WeldOutput:     weldOut,
 		BackendsOutput: bcksOut,
 		TestingOutput:  testingOut,

internal/gen_test.go

@@ -134,6 +134,12 @@ func TestGenerate(t *testing.T) {
 			Name:    "variadic",
 			WorkDir: "example/variadic/state",
 		},
+		{
+			Name:       "transitive-testing",
+			WorkDir:    "example/transitive/state",
+			Tags:       "!dev",
+			ForTesting: true,
+		},
 	}
 
 	for _, test := range tests {

internal/template.go

@@ -32,7 +32,7 @@ var (
 )
 
 // execWeldTpl returns the generated source of the template data.
-func execWeldTpl(data *TplData) ([]byte, error) {
+func execWeldTpl(data TplData) ([]byte, error) {
 	var buf bytes.Buffer
 	err := weldTpl.Execute(&buf, data)
 	if err != nil {
@@ -53,7 +53,9 @@ func execWeldTpl(data *TplData) ([]byte, error) {
 	return src, nil
 }
 
-func execTestingTpl(data *TplData) ([]byte, error) {
+func execTestingTpl(data TplData, bcks Backends) ([]byte, error) {
+	data.Deps = filterTransitiveDeps(data, bcks)
+
 	var buf bytes.Buffer
 	err := testingTpl.Execute(&buf, data)
 	if err != nil {
@@ -74,11 +76,7 @@ func execTestingTpl(data *TplData) ([]byte, error) {
 	return src, nil
 }
 
-func maybeExecBackendsTpl(tplData *TplData, bcks Backends, genBcks bool) ([]byte, error) {
-	if !genBcks {
-		return nil, nil
-	}
-
+func filterTransitiveDeps(tplData TplData, bcks Backends) []TplDep {
 	// Remove transitive deps
 	var deps []TplDep
 	for _, dep := range tplData.Deps {
@@ -94,11 +92,18 @@ func maybeExecBackendsTpl(tplData *TplData, bcks Backends, genBcks bool) ([]byte
 		}
 	}
 
-	clone := *tplData
-	clone.Deps = deps
+	return deps
+}
+
+func maybeExecBackendsTpl(tplData TplData, bcks Backends, genBcks bool) ([]byte, error) {
+	if !genBcks {
+		return nil, nil
+	}
+
+	tplData.Deps = filterTransitiveDeps(tplData, bcks)
 
 	var buf bytes.Buffer
-	err := bcksTpl.Execute(&buf, clone)
+	err := bcksTpl.Execute(&buf, tplData)
 	if err != nil {
 		return nil, err
 	}
@@ -118,14 +123,14 @@ func maybeExecBackendsTpl(tplData *TplData, bcks Backends, genBcks bool) ([]byte
 }
 
 // makeTplData returns the template data for backends and selected nodes.
-func makeTplData(in, out *packages.Package, tags string, selected NodeSelection, specBcks Backends) (*TplData, error) {
+func makeTplData(in, out *packages.Package, tags string, selected NodeSelection, specBcks Backends) (TplData, error) {
 	pkgCache := NewPkgCache(in, out)
 	pkgCache.Add(specBcks.Package)
 
 	unionDeps := union(specBcks, selected.TransitiveBackends)
 	err := sortInDependencyOrder(unionDeps, selected.SelectedNodes, selected.UnselectedTypes)
 	if err != nil {
-		return nil, errors.Wrap(err, "error sorting in dependency order")
+		return TplData{}, errors.Wrap(err, "error sorting in dependency order")
 	}
 
 	// TODO(neil): The deps are now sorted mostly alphabetically, but also in
@@ -141,7 +146,7 @@ func makeTplData(in, out *packages.Package, tags string, selected NodeSelection,
 	for _, param := range selected.UnselectedTypes {
 		v, err := type2Param(param)
 		if err != nil {
-			return nil, err
+			return TplData{}, err
 		}
 		varMap[param.String()] = v
 	}
@@ -161,7 +166,7 @@ func makeTplData(in, out *packages.Package, tags string, selected NodeSelection,
 	for _, dep := range unionDeps {
 		d, err := makeTplDep(pkgCache, selected.SelectedNodes, dep.Getter, dep.Type, varMap)
 		if err != nil {
-			return nil, err
+			return TplData{}, err
 		}
 
 		orig := d.Var
@@ -185,20 +190,20 @@ func makeTplData(in, out *packages.Package, tags string, selected NodeSelection,
 
 	tb, err := makeTplBcks(pkgCache, selected.TransitiveBackends)
 	if err != nil {
-		return nil, err
+		return TplData{}, err
 	}
 
 	bcksTypeRef, err := makeTypeRef(pkgCache, specBcks.Type)
 	if err != nil {
-		return nil, err
+		return TplData{}, err
 	}
 
 	params, err := makeParams(pkgCache, selected.UnselectedTypes)
 	if err != nil {
-		return nil, err
+		return TplData{}, err
 	}
 
-	return &TplData{
+	return TplData{
 		Package:      out.Name,
 		Tags:         tags,
 		BackendsName: specBcks.Name,

internal/templates/testing.tmpl

@@ -26,27 +26,17 @@ type Testing{{.BackendsName}} struct {
 {{end}}{{end}}
 }
 
-{{range .Deps}}
+{{range .Deps}}{{if not .IsDuplicate }}
 func (ti *Testing{{$.BackendsName}}) {{.Getter}}() {{.Type}} {
     if ti.{{.Var}} != nil {
        return ti.{{.Var}}
     }
 
 	return ti.{{$.BackendsName}}.{{.Getter}}()
 }
-{{end}}
-
-{{if .TransBcks -}}
-// Transitive dependency interface assertions.
-var (
-{{range .TransBcks -}}
-	_ {{.}} = (*Testing{{$.BackendsName}})(nil)
-{{end}}
-)
-{{end}}
-
+{{end}}{{end}}
 
-{{range .Deps }}
+{{range .Deps }}{{if not .IsDuplicate }}
 // Set{{.Getter}}ForTesting is a runtime available override for the "{{.Var}}" dependency that should only be used for testing.
 func (ti *Testing{{$.BackendsName}}) Set{{.Getter}}ForTesting(t *testing.T, {{.Var}} {{.Type}}) {
     t.Cleanup(func() {
@@ -55,4 +45,4 @@ func (ti *Testing{{$.BackendsName}}) Set{{.Getter}}ForTesting(t *testing.T, {{.V
 
    	ti.{{.Var}} = {{.Var}}
 }
-{{end}}
+{{end}}{{end}}

internal/testdata/transitive-testing_bcksoutput.golden

@@ -0,0 +1,14 @@
+package state
+
+// Code generated by weld. DO NOT EDIT.
+
+import (
+	transitive_ops "example/transitive/ops"
+)
+
+type Backends interface {
+	Foo() transitive_ops.Foo
+	Qux() transitive_ops.Qux
+	Bar() transitive_ops.Bar
+	Baz() transitive_ops.Baz
+}

internal/testdata/transitive-testing_graph.golden

@@ -0,0 +1,24 @@
+Set[16]: (inline)
+  Set[12]: var example/backends/providers.WeldProd
+    Set[6]: var example/backends/providers.GRPC
+      Set[2]: var example/identity/users/client/grpc.Provider
+        Func[1]: func example/identity/users/client/grpc.New() (*example/identity/users/client/grpc.client, error)
+        Bind[1]: example/identity/users.Client(*example/identity/users/client/grpc.client)
+      Set[2]: var example/identity/email/client/grpc.Provider
+        Func[1]: func example/identity/email/client/grpc.New() (*example/identity/email/client/grpc.client, error)
+        Bind[1]: example/identity/email.Client(*example/identity/email/client/grpc.client)
+      Set[2]: var example/exchange/client/grpc.Provider
+        Func[1]: func example/exchange/client/grpc.New() (*example/exchange/client/grpc.client, error)
+        Bind[1]: example/exchange.Client(*example/exchange/client/grpc.client)
+    Set[3]: var example/backends/providers.DB
+      Func[1]: func example/identity/email/db.Connect() (*example/identity/email/db.EmailDB, error)
+      Func[1]: func example/identity/users/db.Connect() (*example/identity/users/db.UsersDB, error)
+      Func[1]: func example/exchange/db.Connect() (*example/exchange/db.ExchangeDB, error)
+    Set[3]: var example/backends/providers.External
+      Func[1]: func example/external/mail.New(opts ...example/external/mail.option) (*example/external/mail.Mailer, error)
+      Func[1]: func example/external/mail/mail.New() (*example/external/mail/mail.MailerLegacy, error)
+      Func[1]: func example/external/versioned.New() *example/external/versioned/v1.Service
+  Func[1]: func example/transitive/ops.NewFoo() (example/transitive/ops.Foo, error)
+  Func[1]: func example/transitive/ops.NewBar(foo example/transitive/ops.Foo) example/transitive/ops.Bar
+  Func[1]: func example/transitive/ops.NewBaz(bar example/transitive/ops.Bar, qux example/transitive/ops.Qux) example/transitive/ops.Baz
+  Func[1]: func example/transitive/ops.NewQux() (example/transitive/ops.Qux, error)

internal/testdata/transitive-testing_selected.golden

@@ -0,0 +1,4 @@
+Func[1]: func example/transitive/ops.NewBar(foo example/transitive/ops.Foo) example/transitive/ops.Bar
+Func[1]: func example/transitive/ops.NewBaz(bar example/transitive/ops.Bar, qux example/transitive/ops.Qux) example/transitive/ops.Baz
+Func[1]: func example/transitive/ops.NewFoo() (example/transitive/ops.Foo, error)
+Func[1]: func example/transitive/ops.NewQux() (example/transitive/ops.Qux, error)

internal/testdata/transitive-testing_specBack.golden

@@ -0,0 +1 @@
+example/transitive/state.Backends[4]: example/transitive/ops.Bar, example/transitive/ops.Baz, example/transitive/ops.Foo, example/transitive/ops.Qux