Fix spec validation & merge so that default values are correctly applied

Signed-off-by: Solomon Hykes <sh.github.6811@hykes.org>

dagger/component.go

@@ -11,29 +11,24 @@ type Component struct {
 	// Source value for the component, without spec merged
 	// eg. `{ string, #dagger: compute: [{do:"fetch-container", ...}]}`
 	v *Value
-
-	// Annotation value for the component , with spec merged.
-	// -> the contents of #dagger.compute
-	// eg. `compute: [{do:"fetch-container", ...}]`
-	//
-	// The spec is merged at this level because the Cue API
-	//  does not support merging embedded scalar with nested definition.
-	config *Value
 }
 
 func NewComponent(v *Value) (*Component, error) {
-	config := v.Get("#dagger")
-	if !config.Exists() {
-		return nil, os.ErrNotExist
+	if !v.Exists() {
+		// Component value does not exist
+		return nil, ErrNotExist
 	}
-	spec := v.cc.Spec()
-	config, err := spec.Get("#ComponentConfig").Merge(v.Get("#dagger"))
+	if !v.Get("#dagger").Exists() {
+		// Component value exists but has no `#dagger` definition
+		return nil, ErrNotExist
+	}
+	// Validate & merge with spec
+	final, err := v.Finalize(v.cc.Spec().Get("#Component"))
 	if err != nil {
-		return nil, errors.Wrap(err, "invalid component config")
+		return nil, errors.Wrap(err, "invalid component")
 	}
 	return &Component{
-		v:      v,
-		config: config,
+		v: final,
 	}, nil
 }
 
@@ -46,19 +41,6 @@ func (c *Component) Config() *Value {
 	return c.Value().Get("#dagger")
 }
 
-// Verify that this component respects the dagger component spec.
-//
-// NOTE: calling matchSpec("#Component") is not enough because
-//   it does not match embedded scalars.
-func (c *Component) Validate() error {
-	// FIXME: this crashes on `#dagger:compute:_`
-	//  see TestValidateEmptyComponent
-	// Using a workaround for now.
-	// return c.Config().Validate("#ComponentConfig")
-
-	return c.Config().Validate()
-}
-
 // Return this component's compute script.
 func (c *Component) ComputeScript() (*Script, error) {
 	return newScript(c.Config().Get("compute"))

dagger/component_test.go

@@ -40,7 +40,6 @@ foo: #dagger: {}
 // Test that default values in spec are applied at the component level
 // See issue #19
 func TestComponentDefaults(t *testing.T) {
-	t.Skip("FIXME: issue #19")
 	cc := &Compiler{}
 	v, err := cc.Compile("", `
 #dagger: compute: [

dagger/gen.go

@@ -37,11 +37,15 @@ package dagger
 // by scripts defining how to compute it, present it to a user,
 // encrypt it, etc.
 
-// FIXME: #Component will not match embedded scalars.
-//   use Runtime.isComponent() for a reliable check
 #Component: {
+	// Match structs
 	#dagger: #ComponentConfig
 	...
+} | {
+	// Match embedded strings
+	// FIXME: match all embedded scalar types
+	string
+	#dagger: #ComponentConfig
 }
 
 // The contents of a #dagger annotation
@@ -86,7 +90,7 @@ package dagger
 	env?: [string]: string
 	always?: true | *false
 	dir:     string | *"/"
-	mount?: [string]: #MountTmp | #MountCache | #MountComponent | #MountScript
+	mount: [string]: #MountTmp | #MountCache | #MountComponent | #MountScript
 }
 
 #MountTmp:   "tmpfs"

dagger/op_test.go

@@ -40,13 +40,10 @@ func TestCopyMatch(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	op, err := newOp(v)
+	op, err := NewOp(v)
 	if err != nil {
 		t.Fatal(err)
 	}
-	if err := op.Validate("#Copy"); err != nil {
-		t.Fatal(err)
-	}
 	n := 0
 	err = op.Walk(ctx, func(op *Op) error {
 		n++

dagger/script.go

@@ -17,8 +17,8 @@ type Script struct {
 }
 
 func NewScript(v *Value) (*Script, error) {
-	spec := v.cc.Spec().Get("#Script")
-	final, err := spec.Merge(v)
+	// Validate & merge with spec
+	final, err := v.Finalize(v.cc.Spec().Get("#Script"))
 	if err != nil {
 		return nil, errors.Wrap(err, "invalid script")
 	}
@@ -30,8 +30,6 @@ func newScript(v *Value) (*Script, error) {
 	if !v.Exists() {
 		return nil, ErrNotExist
 	}
-	// Assume script is valid.
-	// Spec validation is already done at component creation.
 	return &Script{
 		v: v,
 	}, nil
@@ -66,8 +64,9 @@ func (s *Script) Execute(ctx context.Context, fs FS, out *Fillable) (FS, error)
 			log.
 				Ctx(ctx).
 				Warn().
-				Err(err).
-				Msg("script is unspecified, aborting execution")
+				Int("op", idx).
+				// FIXME: tell user which inputs are missing (by inspecting references)
+				Msg("script is missing inputs and has not been fully executed")
 			return ErrAbortExecution
 		}
 		op, err := newOp(v)

dagger/script_test.go

@@ -6,6 +6,41 @@ import (
 	"testing"
 )
 
+// Test that a script with missing fields DOES NOT cause an error
+// NOTE: this behavior may change in the future.
+func TestScriptMissingFields(t *testing.T) {
+	cc := &Compiler{}
+	s, err := cc.CompileScript("test.cue", `
+		[
+			{
+				do: "fetch-container"
+				// Missing ref, should cause an error
+			}
+		]
+	`)
+	if err != nil {
+		t.Fatalf("err=%v\nval=%v\n", err, s.v.val)
+	}
+}
+
+// Test that a script with defined, but unfinished fields is ignored.
+func TestScriptUnfinishedField(t *testing.T) {
+	// nOps=1 to make sure only 1 op is counted
+	mkScript(t, 1, `
+		[
+			{
+				do: "fetch-container"
+				// Unfinished op: should ignore subsequent ops.
+				ref: string
+			},
+			{
+				do: "exec"
+				args: ["echo", "hello"]
+			}
+		]
+	`)
+}
+
 // Test a script which loads a nested script
 func TestScriptLoadScript(t *testing.T) {
 	mkScript(t, 2, `
@@ -74,7 +109,6 @@ func TestScriptDefaults(t *testing.T) {
 	if dir != "/" {
 		t.Fatal(dir)
 	}
-	t.Skip("FIXME: issue #19")
 	// Walk triggers issue #19 UNLESS optional fields removed from spec.cue
 	if err := op.Walk(context.TODO(), func(op *Op) error {
 		return nil

dagger/spec.cue

@@ -32,11 +32,15 @@ package dagger
 // by scripts defining how to compute it, present it to a user,
 // encrypt it, etc.
 
-// FIXME: #Component will not match embedded scalars.
-//   use Runtime.isComponent() for a reliable check
 #Component: {
+	// Match structs
 	#dagger: #ComponentConfig
 	...
+} | {
+	// Match embedded strings
+	// FIXME: match all embedded scalar types
+	string
+	#dagger: #ComponentConfig
 }
 
 // The contents of a #dagger annotation
@@ -81,7 +85,7 @@ package dagger
 	env?: [string]: string
 	always?: true | *false
 	dir:     string | *"/"
-	mount?: [string]: #MountTmp | #MountCache | #MountComponent | #MountScript
+	mount: [string]: #MountTmp | #MountCache | #MountComponent | #MountScript
 }
 
 #MountTmp:   "tmpfs"

dagger/value.go

@@ -134,6 +134,28 @@ func (v *Value) RangeStruct(fn func(string, *Value) error) error {
 	return nil
 }
 
+// Finalize a value using the given spec. This means:
+//   1. Check that the value matches the spec.
+//   2. Merge the value and the spec, and return the result.
+func (v *Value) Finalize(spec *Value) (*Value, error) {
+	v.cc.Lock()
+	unified := spec.val.Unify(v.val)
+	v.cc.Unlock()
+	// FIXME: temporary debug message, remove before merging.
+	//      fmt.Printf("Finalize:\n  spec=%v\n  v=%v\n  unified=%v", spec.val, v.val, unified)
+
+	// OPTION 1: unfinished fields should pass, but don't
+	// if err := unified.Validate(cue.Concrete(true)); err != nil {
+	// OPTION 2: missing fields should fail, but don't
+	// We choose option 2 for now, because it's easier to layer a
+	// fix on top (we access individual fields so have an opportunity
+	//  to return an error if they are not there).
+	if err := unified.Validate(cue.Final()); err != nil {
+		return nil, cueErr(err)
+	}
+	return v.Merge(spec)
+}
+
 // FIXME: receive string path?
 func (v *Value) Merge(x interface{}, path ...string) (*Value, error) {
 	if xval, ok := x.(*Value); ok {

dagger/value_test.go

@@ -4,6 +4,93 @@ import (
 	"testing"
 )
 
+func TestValueFinalize(t *testing.T) {
+	cc := &Compiler{}
+	root, err := cc.Compile("test.cue",
+		`
+	#FetchContainer: {
+		do: "fetch-container"
+		ref: string
+		tag: string | *"latest"
+	}
+
+	good: {
+		do: "fetch-container"
+		ref: "scratch"
+	}
+
+	missing: {
+		do: "fetch-container"
+		// missing ref
+	}
+
+	unfinished: {
+		do: "fetch-container"
+		ref: string // unfinished but present: should pass validation
+	}
+
+	forbidden: {
+		do: "fetch-container"
+		foo: "bar" // forbidden field
+	}
+	`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	spec := root.Get("#FetchContainer")
+	if _, err := root.Get("good").Finalize(spec); err != nil {
+		// Should not fail
+		t.Errorf("'good': validation should not fail. err=%q", err)
+	}
+	if _, err := root.Get("missing").Finalize(spec); err != nil {
+		// SHOULD NOT fail
+		// NOTE: this behavior may change in the future.
+		t.Errorf("'missing': validation should fail")
+	}
+	if _, err := root.Get("forbidden").Finalize(spec); err == nil {
+		// SHOULD fail
+		t.Errorf("'forbidden': validation should fail")
+	}
+	if _, err := root.Get("unfinished").Finalize(spec); err != nil {
+		// Should not fail
+		t.Errorf("'unfinished': validation should not fail. err=%q", err)
+	}
+}
+
+// Test that a non-existing field is detected correctly
+func TestFieldNotExist(t *testing.T) {
+	cc := &Compiler{}
+	root, err := cc.Compile("test.cue", `foo: "bar"`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if v := root.Get("foo"); !v.Exists() {
+		// value should exist
+		t.Fatal(v)
+	}
+	if v := root.Get("bar"); v.Exists() {
+		// value should NOT exist
+		t.Fatal(v)
+	}
+}
+
+// Test that a non-existing definition is detected correctly
+func TestDefNotExist(t *testing.T) {
+	cc := &Compiler{}
+	root, err := cc.Compile("test.cue", `foo: #bla: "bar"`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if v := root.Get("foo.#bla"); !v.Exists() {
+		// value should exist
+		t.Fatal(v)
+	}
+	if v := root.Get("foo.#nope"); v.Exists() {
+		// value should NOT exist
+		t.Fatal(v)
+	}
+}
+
 func TestSimple(t *testing.T) {
 	cc := &Compiler{}
 	_, err := cc.EmptyStruct()