Enable hooks for dynamic completion (#123)

* Add `CompletionHooks` to `AttributeSchema`
* Add comment about `AnyAttribute`
* Add optional reslove hook to Candidate
* Extend decoder context with completion hooks
* Execute hooks as part of attribue expr candidates
* Add ResolveCandidate to decoder for resolve handler
* Improve quoting and empty/multiline expressions
* Pass context in all existing tests
* Add tests for attr completion hooks

Co-authored-by: Radek Simko <radek.simko@gmail.com>

decoder/body_candidates_test.go

@@ -1,6 +1,7 @@
 package decoder
 
 import (
+	"context"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -12,6 +13,7 @@ import (
 )
 
 func TestDecoder_CandidateAtPos_incompleteAttributes(t *testing.T) {
+	ctx := context.Background()
 	bodySchema := &schema.BodySchema{
 		Blocks: map[string]*schema.BlockSchema{
 			"customblock": {
@@ -43,7 +45,7 @@ func TestDecoder_CandidateAtPos_incompleteAttributes(t *testing.T) {
 	})
 	d.maxCandidates = 1
 
-	candidates, err := d.CandidatesAtPos("test.tf", hcl.Pos{
+	candidates, err := d.CandidatesAtPos(ctx, "test.tf", hcl.Pos{
 		Line:   2,
 		Column: 7,
 		Byte:   29,
@@ -84,6 +86,7 @@ func TestDecoder_CandidateAtPos_incompleteAttributes(t *testing.T) {
 }
 
 func TestDecoder_CandidateAtPos_computedAttributes(t *testing.T) {
+	ctx := context.Background()
 	bodySchema := &schema.BodySchema{
 		Blocks: map[string]*schema.BlockSchema{
 			"customblock": {
@@ -113,7 +116,7 @@ func TestDecoder_CandidateAtPos_computedAttributes(t *testing.T) {
 		},
 	})
 
-	candidates, err := d.CandidatesAtPos("test.tf", hcl.Pos{
+	candidates, err := d.CandidatesAtPos(ctx, "test.tf", hcl.Pos{
 		Line:   2,
 		Column: 7,
 		Byte:   29,
@@ -154,6 +157,7 @@ func TestDecoder_CandidateAtPos_computedAttributes(t *testing.T) {
 }
 
 func TestDecoder_CandidateAtPos_incompleteBlocks(t *testing.T) {
+	ctx := context.Background()
 	bodySchema := &schema.BodySchema{
 		Blocks: map[string]*schema.BlockSchema{
 			"customblock": {
@@ -186,7 +190,7 @@ func TestDecoder_CandidateAtPos_incompleteBlocks(t *testing.T) {
 	})
 	d.maxCandidates = 1
 
-	candidates, err := d.CandidatesAtPos("test.tf", hcl.Pos{
+	candidates, err := d.CandidatesAtPos(ctx, "test.tf", hcl.Pos{
 		Line:   3,
 		Column: 8,
 		Byte:   42,
@@ -227,6 +231,7 @@ func TestDecoder_CandidateAtPos_incompleteBlocks(t *testing.T) {
 }
 
 func TestDecoder_CandidateAtPos_duplicateNames(t *testing.T) {
+	ctx := context.Background()
 	bodySchema := &schema.BodySchema{
 		Attributes: map[string]*schema.AttributeSchema{
 			"ingress": {
@@ -258,7 +263,7 @@ func TestDecoder_CandidateAtPos_duplicateNames(t *testing.T) {
 		},
 	})
 
-	candidates, err := d.CandidatesAtPos("test.tf", hcl.InitialPos)
+	candidates, err := d.CandidatesAtPos(ctx, "test.tf", hcl.InitialPos)
 	if err != nil {
 		t.Fatal(err)
 	}

decoder/candidates.go

@@ -1,6 +1,7 @@
 package decoder
 
 import (
+	"context"
 	"fmt"
 
 	"github.com/hashicorp/hcl-lang/lang"
@@ -13,7 +14,7 @@ import (
 //
 // Schema is required in order to return any candidates and method will return
 // error if there isn't one.
-func (d *PathDecoder) CandidatesAtPos(filename string, pos hcl.Pos) (lang.Candidates, error) {
+func (d *PathDecoder) CandidatesAtPos(ctx context.Context, filename string, pos hcl.Pos) (lang.Candidates, error) {
 	f, err := d.fileByName(filename)
 	if err != nil {
 		return lang.ZeroCandidates(), err
@@ -37,10 +38,10 @@ func (d *PathDecoder) CandidatesAtPos(filename string, pos hcl.Pos) (lang.Candid
 		outerBodyRng = ob.Range()
 	}
 
-	return d.candidatesAtPos(rootBody, outerBodyRng, d.pathCtx.Schema, pos)
+	return d.candidatesAtPos(ctx, rootBody, outerBodyRng, d.pathCtx.Schema, pos)
 }
 
-func (d *PathDecoder) candidatesAtPos(body *hclsyntax.Body, outerBodyRng hcl.Range, bodySchema *schema.BodySchema, pos hcl.Pos) (lang.Candidates, error) {
+func (d *PathDecoder) candidatesAtPos(ctx context.Context, body *hclsyntax.Body, outerBodyRng hcl.Range, bodySchema *schema.BodySchema, pos hcl.Pos) (lang.Candidates, error) {
 	if bodySchema == nil {
 		return lang.ZeroCandidates(), nil
 	}
@@ -50,10 +51,10 @@ func (d *PathDecoder) candidatesAtPos(body *hclsyntax.Body, outerBodyRng hcl.Ran
 	for _, attr := range body.Attributes {
 		if d.isPosInsideAttrExpr(attr, pos) {
 			if aSchema, ok := bodySchema.Attributes[attr.Name]; ok {
-				return d.attrValueCandidatesAtPos(attr, aSchema, outerBodyRng, pos)
+				return d.attrValueCandidatesAtPos(ctx, attr, aSchema, outerBodyRng, pos)
 			}
 			if bodySchema.AnyAttribute != nil {
-				return d.attrValueCandidatesAtPos(attr, bodySchema.AnyAttribute, outerBodyRng, pos)
+				return d.attrValueCandidatesAtPos(ctx, attr, bodySchema.AnyAttribute, outerBodyRng, pos)
 			}
 
 			return lang.ZeroCandidates(), nil
@@ -132,7 +133,7 @@ func (d *PathDecoder) candidatesAtPos(body *hclsyntax.Body, outerBodyRng hcl.Ran
 					return lang.ZeroCandidates(), err
 				}
 
-				return d.candidatesAtPos(block.Body, outerBodyRng, mergedSchema, pos)
+				return d.candidatesAtPos(ctx, block.Body, outerBodyRng, mergedSchema, pos)
 			}
 		}
 	}