From 5d2496e37c4a38be885b1e05287e86c99ea88775 Mon Sep 17 00:00:00 2001
From: Radek Simko <radek.simko@gmail.com>
Date: Wed, 16 Jun 2021 12:35:28 +0100
Subject: [PATCH] schema/decoder: Make label completion more flexible

---
 decoder/candidates.go      |  6 ++++
 decoder/candidates_test.go | 65 +++++++++++++++++++++++++++++++++-----
 schema/label_schema.go     |  6 ++++
 3 files changed, 69 insertions(+), 8 deletions(-)

diff --git a/decoder/candidates.go b/decoder/candidates.go
index a124ecc7..1059c74f 100644
--- a/decoder/candidates.go
+++ b/decoder/candidates.go
@@ -111,6 +111,12 @@ func (d *Decoder) candidatesAtPos(body *hclsyntax.Body, outerBodyRng hcl.Range,
 					}
 					prefixRng.End = pos
 
+					labelSchema := bSchema.Labels[i]
+
+					if !labelSchema.Completable {
+						return lang.ZeroCandidates(), nil
+					}
+
 					return d.labelCandidatesFromDependentSchema(i, bSchema.DependentBody, prefixRng, rng)
 				}
 			}
diff --git a/decoder/candidates_test.go b/decoder/candidates_test.go
index 22b6c47c..b15cfb9b 100644
--- a/decoder/candidates_test.go
+++ b/decoder/candidates_test.go
@@ -135,7 +135,7 @@ func TestDecoder_CandidatesAtPos_nilBodySchema(t *testing.T) {
 				Blocks: map[string]*schema.BlockSchema{
 					"resource": {
 						Labels: []*schema.LabelSchema{
-							{Name: "type", IsDepKey: true},
+							{Name: "type", IsDepKey: true, Completable: true},
 							{Name: "name"},
 						},
 						Body: nil,
@@ -495,7 +495,7 @@ func TestDecoder_CandidatesAtPos_rightHandSideInString(t *testing.T) {
 func TestDecoder_CandidatesAtPos_endOfLabel(t *testing.T) {
 	blockSchema := &schema.BlockSchema{
 		Labels: []*schema.LabelSchema{
-			{Name: "type"},
+			{Name: "type", Completable: true},
 		},
 		DependentBody: map[schema.SchemaKey]*schema.BodySchema{
 			schema.NewSchemaKey(schema.DependencyKeys{
@@ -595,9 +595,58 @@ func TestDecoder_CandidatesAtPos_endOfLabel(t *testing.T) {
 	}
 }
 
+func TestDecoder_CandidatesAtPos_nonCompletableLabel(t *testing.T) {
+	blockSchema := &schema.BlockSchema{
+		Labels: []*schema.LabelSchema{
+			{Name: "type", IsDepKey: true},
+		},
+		DependentBody: map[schema.SchemaKey]*schema.BodySchema{
+			schema.NewSchemaKey(schema.DependencyKeys{
+				Labels: []schema.LabelDependent{
+					{Index: 0, Value: "myfirst"},
+				},
+			}): {},
+			schema.NewSchemaKey(schema.DependencyKeys{
+				Labels: []schema.LabelDependent{
+					{Index: 0, Value: "mysecond"},
+				},
+			}): {},
+		},
+	}
+	bodySchema := &schema.BodySchema{
+		Blocks: map[string]*schema.BlockSchema{
+			"myblock": blockSchema,
+		},
+	}
+	testConfig := []byte(`myblock "" {
+}
+`)
+
+	d := NewDecoder()
+	d.SetSchema(bodySchema)
+	f, _ := hclsyntax.ParseConfig(testConfig, "test.tf", hcl.InitialPos)
+	err := d.LoadFile("test.tf", f)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	candidates, err := d.CandidatesAtPos("test.tf", hcl.Pos{
+		Line:   1,
+		Column: 10,
+		Byte:   9,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	expectedCandidates := lang.ZeroCandidates()
+	if diff := cmp.Diff(expectedCandidates, candidates); diff != "" {
+		t.Fatalf("unexpected candidates: %s", diff)
+	}
+}
+
 func TestDecoder_CandidatesAtPos_zeroByteContent(t *testing.T) {
 	resourceLabelSchema := []*schema.LabelSchema{
-		{Name: "type", IsDepKey: true},
+		{Name: "type", IsDepKey: true, Completable: true},
 		{Name: "name"},
 	}
 	resourceSchema := &schema.BlockSchema{
@@ -653,7 +702,7 @@ func TestDecoder_CandidatesAtPos_zeroByteContent(t *testing.T) {
 
 func TestDecoder_CandidatesAtPos_endOfFilePos(t *testing.T) {
 	resourceLabelSchema := []*schema.LabelSchema{
-		{Name: "type", IsDepKey: true},
+		{Name: "type", IsDepKey: true, Completable: true},
 		{Name: "name"},
 	}
 	resourceSchema := &schema.BlockSchema{
@@ -717,7 +766,7 @@ func TestDecoder_CandidatesAtPos_endOfFilePos(t *testing.T) {
 
 func TestDecoder_CandidatesAtPos_emptyLabel(t *testing.T) {
 	resourceLabelSchema := []*schema.LabelSchema{
-		{Name: "type", IsDepKey: true},
+		{Name: "type", IsDepKey: true, Completable: true},
 		{Name: "name"},
 	}
 	resourceSchema := &schema.BlockSchema{
@@ -811,7 +860,7 @@ func TestDecoder_CandidatesAtPos_emptyLabel(t *testing.T) {
 
 func TestDecoder_CandidatesAtPos_emptyLabel_duplicateDepKeys(t *testing.T) {
 	resourceLabelSchema := []*schema.LabelSchema{
-		{Name: "type", IsDepKey: true},
+		{Name: "type", IsDepKey: true, Completable: true},
 		{Name: "name"},
 	}
 	resourceSchema := &schema.BlockSchema{
@@ -903,7 +952,7 @@ func TestDecoder_CandidatesAtPos_emptyLabel_duplicateDepKeys(t *testing.T) {
 
 func TestDecoder_CandidatesAtPos_basic(t *testing.T) {
 	resourceLabelSchema := []*schema.LabelSchema{
-		{Name: "type", IsDepKey: true},
+		{Name: "type", IsDepKey: true, Completable: true},
 		{Name: "name"},
 	}
 
@@ -1287,7 +1336,7 @@ func TestDecoder_CandidatesAtPos_AnyAttribute(t *testing.T) {
 
 func TestDecoder_CandidatesAtPos_multipleTypes(t *testing.T) {
 	resourceLabelSchema := []*schema.LabelSchema{
-		{Name: "type", IsDepKey: true},
+		{Name: "type", IsDepKey: true, Completable: true},
 		{Name: "name"},
 	}
 
diff --git a/schema/label_schema.go b/schema/label_schema.go
index 3cdf605e..5f83c16f 100644
--- a/schema/label_schema.go
+++ b/schema/label_schema.go
@@ -12,6 +12,11 @@ type LabelSchema struct {
 	// IsDepKey describes whether to use this label as key
 	// when looking up dependent schema
 	IsDepKey bool
+
+	// In cases where label's IsDepKey=true any DependentKey label values
+	// within Blocks's DependentBody can be used for completion
+	// This enables such behaviour.
+	Completable bool
 }
 
 func (*LabelSchema) isSchemaImpl() schemaImplSigil {
@@ -25,6 +30,7 @@ func (ls *LabelSchema) Copy() *LabelSchema {
 
 	return &LabelSchema{
 		Name:        ls.Name,
+		Completable: ls.Completable,
 		Description: ls.Description,
 		IsDepKey:    ls.IsDepKey,
 	}