decoder: Ensure partially unknown dependent body is handled (#339)

* decoder: Ensure partially unknown dependent body is handled

* decoder: Report merging result as enum instead of boolean

decoder/hover.go

@@ -163,8 +163,8 @@ func (d *PathDecoder) hoverContentForLabel(i int, block *hclsyntax.Block, bSchem
 	labelSchema := bSchema.Labels[i]
 
 	if labelSchema.IsDepKey {
-		bs, _, ok := schemahelper.NewBlockSchema(bSchema).DependentBodySchema(block.AsHCLBlock())
-		if ok {
+		bs, _, result := schemahelper.NewBlockSchema(bSchema).DependentBodySchema(block.AsHCLBlock())
+		if result == schemahelper.LookupSuccessful || result == schemahelper.LookupPartiallySuccessful {
 			content := fmt.Sprintf("`%s`", value)
 			if bs.Detail != "" {
 				content += " " + bs.Detail

decoder/internal/schemahelper/block_schema.go

@@ -8,7 +8,7 @@ import (
 	"github.com/hashicorp/hcl/v2"
 )
 
-func MergeBlockBodySchemas(block *hcl.Block, blockSchema *schema.BlockSchema) (*schema.BodySchema, bool) {
+func MergeBlockBodySchemas(block *hcl.Block, blockSchema *schema.BlockSchema) (*schema.BodySchema, LookupResult) {
 	mergedSchema := &schema.BodySchema{}
 	if blockSchema.Body != nil {
 		mergedSchema = blockSchema.Body.Copy()
@@ -26,8 +26,8 @@ func MergeBlockBodySchemas(block *hcl.Block, blockSchema *schema.BlockSchema) (*
 		mergedSchema.ImpliedOrigins = make([]schema.ImpliedOrigin, 0)
 	}
 
-	depSchema, depKeys, ok := NewBlockSchema(blockSchema).DependentBodySchema(block)
-	if ok {
+	depSchema, _, result := NewBlockSchema(blockSchema).DependentBodySchema(block)
+	if result == LookupSuccessful || result == LookupPartiallySuccessful {
 		for name, attr := range depSchema.Attributes {
 			if _, exists := mergedSchema.Attributes[name]; !exists {
 				mergedSchema.Attributes[name] = attr
@@ -71,7 +71,7 @@ func MergeBlockBodySchemas(block *hcl.Block, blockSchema *schema.BlockSchema) (*
 		if depSchema.Extensions != nil {
 			mergedSchema.Extensions = depSchema.Extensions.Copy()
 		}
-	} else if !ok && mergedSchema.Extensions != nil && mergedSchema.Extensions.DynamicBlocks && len(mergedSchema.Blocks) > 0 {
+	} else if (result == LookupFailed || result == NoDependentKeys) && mergedSchema.Extensions != nil && mergedSchema.Extensions.DynamicBlocks && len(mergedSchema.Blocks) > 0 {
 		// dynamic blocks are only relevant for dependent schemas,
 		// but we may end up here because the schema is a result
 		// of merged static + dependent schema from previous iteration
@@ -90,10 +90,5 @@ func MergeBlockBodySchemas(block *hcl.Block, blockSchema *schema.BlockSchema) (*
 		mergedSchema.Blocks["dynamic"] = buildDynamicBlockSchema(mergedSchema)
 	}
 
-	expectedDepBody := len(depKeys.Labels) > 0 || len(depKeys.Attributes) > 0
-
-	// report success either if there wasn't any dependent body merging to do
-	// or if the merging was successful
-
-	return mergedSchema, !expectedDepBody || ok
+	return mergedSchema, result
 }

decoder/internal/schemahelper/dependent_body.go

@@ -12,6 +12,15 @@ import (
 	"github.com/zclconf/go-cty/cty"
 )
 
+type LookupResult int
+
+const (
+	LookupFailed LookupResult = iota
+	LookupSuccessful
+	LookupPartiallySuccessful
+	NoDependentKeys
+)
+
 type blockSchema struct {
 	*schema.BlockSchema
 	seenNestedDepKeys bool
@@ -23,16 +32,23 @@ func NewBlockSchema(bs *schema.BlockSchema) blockSchema {
 
 // DependentBodySchema finds relevant BodySchema based on dependency keys
 // such as a label or an attribute (or combination of both).
-func (bs blockSchema) DependentBodySchema(block *hcl.Block) (*schema.BodySchema, schema.DependencyKeys, bool) {
+func (bs blockSchema) DependentBodySchema(block *hcl.Block) (*schema.BodySchema, schema.DependencyKeys, LookupResult) {
+	result := LookupFailed
+
 	dks := dependencyKeysFromBlock(block, bs)
 	b, err := dks.MarshalJSON()
 	if err != nil {
-		return nil, schema.DependencyKeys{}, false
+		return nil, schema.DependencyKeys{}, result
+	}
+
+	if len(dks.Labels) == 0 && len(dks.Attributes) == 0 {
+		return bs.Body, schema.DependencyKeys{}, NoDependentKeys
 	}
 
 	key := schema.SchemaKey(string(b))
 	depBodySchema, ok := bs.DependentBody[key]
 	if ok {
+		result = LookupSuccessful
 		hasDepKeys := false
 		for _, attr := range depBodySchema.Attributes {
 			if attr.IsDepKey {
@@ -44,13 +60,17 @@ func (bs blockSchema) DependentBodySchema(block *hcl.Block) (*schema.BodySchema,
 			mergedBlockSchema := NewBlockSchema(bs.Copy())
 			mergedBlockSchema.seenNestedDepKeys = true
 			mergedBlockSchema.Body = depBodySchema
-			if depBodySchema, dks, ok := mergedBlockSchema.DependentBodySchema(block); ok {
-				return depBodySchema, dks, ok
+			if depBodySchema, dks, nestedOk := mergedBlockSchema.DependentBodySchema(block); nestedOk == LookupSuccessful {
+				return depBodySchema, dks, LookupSuccessful
+			} else {
+				// Ensure we report lookup failure overall if we couldn't
+				// lookup nested dependent body
+				result = LookupPartiallySuccessful
 			}
 		}
 	}
 
-	return depBodySchema, dks, ok
+	return depBodySchema, dks, result
 }
 
 func dependencyKeysFromBlock(block *hcl.Block, blockSchema blockSchema) schema.DependencyKeys {

decoder/internal/schemahelper/dependent_body_test.go

@@ -52,8 +52,8 @@ func TestBodySchema_DependentBodySchema_label_basic(t *testing.T) {
 		},
 	}
 
-	bodySchema, _, ok := NewBlockSchema(bSchema).DependentBodySchema(block)
-	if !ok {
+	bodySchema, _, result := NewBlockSchema(bSchema).DependentBodySchema(block)
+	if result != LookupSuccessful {
 		t.Fatal("expected to find body schema for 'theircloud' label")
 	}
 	expectedSchema := &schema.BodySchema{
@@ -104,8 +104,8 @@ func TestBodySchema_DependentBodySchema_mismatchingLabels(t *testing.T) {
 		},
 	}
 
-	_, _, ok := NewBlockSchema(bSchema).DependentBodySchema(block)
-	if ok {
+	_, _, result := NewBlockSchema(bSchema).DependentBodySchema(block)
+	if result != LookupFailed {
 		t.Fatal("expected to not find body schema for mismatching label schema")
 	}
 }
@@ -170,17 +170,17 @@ func TestBodySchema_DependentBodySchema_dependentAttr(t *testing.T) {
 		},
 	}
 
-	bodySchema, _, ok := NewBlockSchema(bSchema).DependentBodySchema(&hcl.Block{
+	bodySchema, _, result := NewBlockSchema(bSchema).DependentBodySchema(&hcl.Block{
 		Labels: []string{"remote_state"},
 	})
-	if !ok {
+	if result != LookupSuccessful {
 		t.Fatal("expected to find body schema for nested dependent schema")
 	}
 	if diff := cmp.Diff(firstDepBody, bodySchema, ctydebug.CmpOptions); diff != "" {
 		t.Fatalf("mismatching body schema: %s", diff)
 	}
 
-	bodySchema, _, ok = NewBlockSchema(bSchema).DependentBodySchema(&hcl.Block{
+	bodySchema, _, result = NewBlockSchema(bSchema).DependentBodySchema(&hcl.Block{
 		Labels: []string{"remote_state"},
 		Body: &hclsyntax.Body{
 			Attributes: hclsyntax.Attributes{
@@ -193,7 +193,7 @@ func TestBodySchema_DependentBodySchema_dependentAttr(t *testing.T) {
 			},
 		},
 	})
-	if !ok {
+	if result != LookupSuccessful {
 		t.Fatal("expected to find body schema for nested dependent schema")
 	}
 	if diff := cmp.Diff(secondDepBody, bodySchema, ctydebug.CmpOptions); diff != "" {
@@ -256,7 +256,7 @@ func TestBodySchema_DependentBodySchema_missingDependentAttr(t *testing.T) {
 		},
 	}
 
-	bodySchema, _, ok := NewBlockSchema(bSchema).DependentBodySchema(&hcl.Block{
+	bodySchema, _, result := NewBlockSchema(bSchema).DependentBodySchema(&hcl.Block{
 		Labels: []string{"remote_state"},
 		Body: &hclsyntax.Body{
 			Attributes: hclsyntax.Attributes{
@@ -267,8 +267,8 @@ func TestBodySchema_DependentBodySchema_missingDependentAttr(t *testing.T) {
 			},
 		},
 	})
-	if !ok {
-		t.Fatal("expected to find first body schema for missing keys")
+	if result != LookupPartiallySuccessful {
+		t.Fatalf("expected to find first body schema for missing keys; reported: %q", result)
 	}
 	if diff := cmp.Diff(firstDepBody, bodySchema, ctydebug.CmpOptions); diff != "" {
 		t.Fatalf("mismatching body schema: %s", diff)
@@ -418,8 +418,8 @@ func TestBodySchema_DependentBodySchema_attributes(t *testing.T) {
 					Attributes: tc.attributes,
 				},
 			}
-			bodySchema, _, ok := tc.schema.DependentBodySchema(block)
-			if !ok {
+			bodySchema, _, result := tc.schema.DependentBodySchema(block)
+			if result != LookupSuccessful {
 				t.Fatalf("expected to find body schema for given block with %d attributes",
 					len(tc.attributes))
 			}
@@ -430,13 +430,86 @@ func TestBodySchema_DependentBodySchema_attributes(t *testing.T) {
 	}
 }
 
+func TestBodySchema_DependentBodySchema_partialMergeFailure(t *testing.T) {
+	testSchema := NewBlockSchema(&schema.BlockSchema{
+		Labels: []*schema.LabelSchema{
+			{
+				Name:     "type",
+				IsDepKey: true,
+			},
+		},
+		Body: &schema.BodySchema{
+			Attributes: map[string]*schema.AttributeSchema{
+				"count": {
+					Constraint: schema.AnyExpression{OfType: cty.Number},
+				},
+			},
+		},
+		DependentBody: map[schema.SchemaKey]*schema.BodySchema{
+			schema.NewSchemaKey(schema.DependencyKeys{
+				Labels: []schema.LabelDependent{
+					{
+						Index: 0,
+						Value: "terraform_remote_state",
+					},
+				},
+			}): {
+				Attributes: map[string]*schema.AttributeSchema{
+					"first": {
+						Constraint: schema.LiteralType{Type: cty.String},
+					},
+					"backend": {
+						Constraint: schema.AnyExpression{OfType: cty.String},
+						IsDepKey:   true,
+					},
+				},
+			},
+			schema.NewSchemaKey(schema.DependencyKeys{
+				Attributes: []schema.AttributeDependent{
+					{
+						Name: "backend",
+						Expr: schema.ExpressionValue{
+							Static: cty.StringVal("remote"),
+						},
+					},
+				},
+			}): {
+				Attributes: map[string]*schema.AttributeSchema{
+					"second": {Constraint: schema.LiteralType{Type: cty.String}},
+				},
+			},
+		},
+	})
+
+	block := &hcl.Block{
+		Labels: []string{"terraform_remote_state"},
+		Body: &hclsyntax.Body{
+			Attributes: map[string]*hclsyntax.Attribute{
+				"backend": {
+					Name: "backend",
+					Expr: &hclsyntax.ScopeTraversalExpr{
+						Traversal: hcl.Traversal{
+							hcl.TraverseRoot{Name: "referencestep"},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	_, result := MergeBlockBodySchemas(block, testSchema.BlockSchema)
+	if result != LookupPartiallySuccessful {
+		t.Fatal("expected partially failed dependent body lookup to fail")
+	}
+}
+
 func TestBodySchema_DependentBodySchema_label_notFound(t *testing.T) {
 	block := &hcl.Block{
 		Labels: []string{"test", "mycloud"},
 		Body:   hcl.EmptyBody(),
 	}
-	_, _, ok := testSchemaWithLabels.DependentBodySchema(block)
-	if ok {
+	_, _, result := testSchemaWithLabels.DependentBodySchema(block)
+	if result != LookupFailed {
 		t.Fatal("expected not to find body schema for 'mycloud' 2nd label")
 	}
 }
@@ -446,8 +519,8 @@ func TestBodySchema_DependentBodySchema_label_storedUnsorted(t *testing.T) {
 		Labels: []string{"complexcloud", "pumpkin"},
 		Body:   hcl.EmptyBody(),
 	}
-	bodySchema, _, ok := testSchemaWithLabels.DependentBodySchema(block)
-	if !ok {
+	bodySchema, _, result := testSchemaWithLabels.DependentBodySchema(block)
+	if result != LookupSuccessful {
 		t.Fatal("expected to find body schema stored with unsorted keys")
 	}
 	expectedSchema := &schema.BodySchema{
@@ -465,8 +538,8 @@ func TestBodySchema_DependentBodySchema_label_lookupUnsorted(t *testing.T) {
 		Labels: []string{"apple", "crazycloud"},
 		Body:   hcl.EmptyBody(),
 	}
-	_, _, ok := testSchemaWithLabels.DependentBodySchema(block)
-	if ok {
+	_, _, result := testSchemaWithLabels.DependentBodySchema(block)
+	if result != LookupFailed {
 		t.Fatal("expected to not find body schema based on wrongly sorted labels")
 	}
 }

decoder/internal/walker/walker.go

@@ -88,8 +88,8 @@ func Walk(ctx context.Context, node hclsyntax.Node, nodeSchema schema.Schema, w
 		var blockBodySchema schema.Schema = nil
 		bSchema, ok := nodeSchema.(*schema.BlockSchema)
 		if ok && bSchema.Body != nil {
-			mergedSchema, ok := schemahelper.MergeBlockBodySchemas(nodeType.AsHCLBlock(), bSchema)
-			if !ok {
+			mergedSchema, result := schemahelper.MergeBlockBodySchemas(nodeType.AsHCLBlock(), bSchema)
+			if result == schemahelper.LookupFailed || result == schemahelper.LookupPartiallySuccessful {
 				ctx = schemacontext.WithUnknownSchema(ctx)
 			}
 			blockBodySchema = mergedSchema

decoder/links.go

@@ -46,8 +46,8 @@ func (d *PathDecoder) linksInBody(body *hclsyntax.Body, bodySchema *schema.BodyS
 
 		// Currently only block bodies have links associated
 		if block.Body != nil {
-			depSchema, dk, ok := schemahelper.NewBlockSchema(blockSchema).DependentBodySchema(block.AsHCLBlock())
-			if ok && depSchema.DocsLink != nil {
+			depSchema, dk, result := schemahelper.NewBlockSchema(blockSchema).DependentBodySchema(block.AsHCLBlock())
+			if (result == schemahelper.LookupSuccessful || result == schemahelper.LookupPartiallySuccessful || result == schemahelper.NoDependentKeys) && depSchema.DocsLink != nil {
 				link := depSchema.DocsLink
 				u, err := d.docsURL(link.URL, "documentLink")
 				if err != nil {

decoder/reference_targets.go

@@ -201,8 +201,8 @@ func (d *PathDecoder) decodeReferenceTargetsForBody(body hcl.Body, parentBlock *
 				}
 			}
 
-			depSchema, _, ok := schemahelper.NewBlockSchema(bSchema).DependentBodySchema(blk.Block)
-			if ok {
+			depSchema, _, result := schemahelper.NewBlockSchema(bSchema).DependentBodySchema(blk.Block)
+			if result == schemahelper.LookupSuccessful {
 				fullSchema := depSchema
 				if bSchema.Address.BodyAsData {
 					mergedSchema, _ := schemahelper.MergeBlockBodySchemas(blk.Block, bSchema)