From 1aaa58b151ff62c95a30a6bb871e17119f3bab1d Mon Sep 17 00:00:00 2001
From: Radek Simko <radek.simko@gmail.com>
Date: Tue, 24 Jan 2023 13:47:14 +0200
Subject: [PATCH] decoder: Implement semantic tokens for Keyword

---
 decoder/expr_keyword.go             |   8 --
 decoder/expr_keyword_semtok.go      |  31 +++++++
 decoder/expr_keyword_semtok_test.go | 123 ++++++++++++++++++++++++++++
 3 files changed, 154 insertions(+), 8 deletions(-)
 create mode 100644 decoder/expr_keyword_semtok.go
 create mode 100644 decoder/expr_keyword_semtok_test.go

diff --git a/decoder/expr_keyword.go b/decoder/expr_keyword.go
index 8c66655d..aebd3888 100644
--- a/decoder/expr_keyword.go
+++ b/decoder/expr_keyword.go
@@ -1,9 +1,6 @@
 package decoder
 
 import (
-	"context"
-
-	"github.com/hashicorp/hcl-lang/lang"
 	"github.com/hashicorp/hcl-lang/schema"
 	"github.com/hashicorp/hcl/v2"
 )
@@ -12,8 +9,3 @@ type Keyword struct {
 	expr hcl.Expression
 	cons schema.Keyword
 }
-
-func (kw Keyword) SemanticTokens(ctx context.Context) []lang.SemanticToken {
-	// TODO
-	return nil
-}
diff --git a/decoder/expr_keyword_semtok.go b/decoder/expr_keyword_semtok.go
new file mode 100644
index 00000000..cc065cb6
--- /dev/null
+++ b/decoder/expr_keyword_semtok.go
@@ -0,0 +1,31 @@
+package decoder
+
+import (
+	"context"
+
+	"github.com/hashicorp/hcl-lang/lang"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+)
+
+func (kw Keyword) SemanticTokens(ctx context.Context) []lang.SemanticToken {
+	eType, ok := kw.expr.(*hclsyntax.ScopeTraversalExpr)
+	if !ok {
+		return []lang.SemanticToken{}
+	}
+
+	if len(eType.Traversal) != 1 {
+		return []lang.SemanticToken{}
+	}
+
+	if eType.Traversal.RootName() == kw.cons.Keyword {
+		return []lang.SemanticToken{
+			{
+				Type:      lang.TokenKeyword,
+				Modifiers: []lang.SemanticTokenModifier{},
+				Range:     eType.Range(),
+			},
+		}
+	}
+
+	return []lang.SemanticToken{}
+}
diff --git a/decoder/expr_keyword_semtok_test.go b/decoder/expr_keyword_semtok_test.go
new file mode 100644
index 00000000..4911ee98
--- /dev/null
+++ b/decoder/expr_keyword_semtok_test.go
@@ -0,0 +1,123 @@
+package decoder
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/hashicorp/hcl-lang/lang"
+	"github.com/hashicorp/hcl-lang/schema"
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/hcl/v2/hclsyntax"
+)
+
+func TestSemanticTokens_exprKeyword(t *testing.T) {
+	testCases := []struct {
+		testName               string
+		attrSchema             map[string]*schema.AttributeSchema
+		cfg                    string
+		expectedSemanticTokens []lang.SemanticToken
+	}{
+		{
+			"mismatching expression type",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.Keyword{
+						Keyword: "foobar",
+					},
+				},
+			},
+			`attr = "foobar"`,
+			[]lang.SemanticToken{
+				{
+					Type:      "hcl-attrName",
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 1, Byte: 0},
+						End:      hcl.Pos{Line: 1, Column: 5, Byte: 4},
+					},
+				},
+			},
+		},
+		{
+			"mismatching keyword",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.Keyword{
+						Keyword: "foobar",
+					},
+				},
+			},
+			`attr = barfoo`,
+			[]lang.SemanticToken{
+				{
+					Type:      "hcl-attrName",
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 1, Byte: 0},
+						End:      hcl.Pos{Line: 1, Column: 5, Byte: 4},
+					},
+				},
+			},
+		},
+		{
+			"matching keyword",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.Keyword{
+						Keyword: "foobar",
+					},
+				},
+			},
+			`attr = foobar`,
+			[]lang.SemanticToken{
+				{
+					Type:      "hcl-attrName",
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 1, Byte: 0},
+						End:      hcl.Pos{Line: 1, Column: 5, Byte: 4},
+					},
+				},
+				{
+					Type:      "hcl-keyword",
+					Modifiers: lang.SemanticTokenModifiers{},
+					Range: hcl.Range{
+						Filename: "test.tf",
+						Start:    hcl.Pos{Line: 1, Column: 8, Byte: 7},
+						End:      hcl.Pos{Line: 1, Column: 14, Byte: 13},
+					},
+				},
+			},
+		},
+	}
+	for i, tc := range testCases {
+		t.Run(fmt.Sprintf("%d-%s", i, tc.testName), func(t *testing.T) {
+			bodySchema := &schema.BodySchema{
+				Attributes: tc.attrSchema,
+			}
+
+			f, _ := hclsyntax.ParseConfig([]byte(tc.cfg), "test.tf", hcl.InitialPos)
+			d := testPathDecoder(t, &PathContext{
+				Schema: bodySchema,
+				Files: map[string]*hcl.File{
+					"test.tf": f,
+				},
+			})
+
+			ctx := context.Background()
+			tokens, err := d.SemanticTokensInFile(ctx, "test.tf")
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if diff := cmp.Diff(tc.expectedSemanticTokens, tokens); diff != "" {
+				t.Fatalf("unexpected tokens: %s", diff)
+			}
+		})
+	}
+}