Fix prefix completion in TemplateWrapExpr (#371)

* decoder: Test cases for prefix in template wrap * decoder: Improve prefix detection for TemplateWrapExpr
hashicorp · Feb 7, 2024 · e8e6de1 · e8e6de1
1 parent 6a6bede
commit e8e6de1
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Showing 2 changed files with 101 additions and 2 deletions.
diff --git a/decoder/expr_any_completion_test.go b/decoder/expr_any_completion_test.go
@@ -4806,7 +4806,7 @@ func TestCompletionAtPos_exprAny_template(t *testing.T) {
 		expectedCandidates lang.Candidates
 	}{
 		{
-			"simple empty template",
+			"simple empty template (wrapped)",
 			map[string]*schema.AttributeSchema{
 				"attr": {
 					Constraint: schema.AnyExpression{
@@ -4923,6 +4923,92 @@ func TestCompletionAtPos_exprAny_template(t *testing.T) {
 				},
 			}),
 		},
+		{
+			"simple empty template with prefix (wrapped)",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.AnyExpression{
+						OfType: cty.String,
+					},
+				},
+			},
+			reference.Targets{
+				{
+					Addr: lang.Address{
+						lang.RootStep{Name: "var"},
+						lang.AttrStep{Name: "bar"},
+					},
+					RangePtr: &hcl.Range{
+						Filename: "variables.tf",
+						Start:    hcl.Pos{Line: 2, Column: 1, Byte: 17},
+						End:      hcl.Pos{Line: 2, Column: 3, Byte: 19},
+					},
+					Type: cty.String,
+				},
+			},
+			`attr = "${v}"
+`,
+			hcl.Pos{Line: 1, Column: 12, Byte: 11},
+			lang.CompleteCandidates([]lang.Candidate{
+				{
+					Label:  "var.bar",
+					Detail: "string",
+					Kind:   lang.ReferenceCandidateKind,
+					TextEdit: lang.TextEdit{
+						NewText: "var.bar",
+						Snippet: "var.bar",
+						Range: hcl.Range{
+							Filename: "test.tf",
+							Start:    hcl.Pos{Line: 1, Column: 11, Byte: 10},
+							End:      hcl.Pos{Line: 1, Column: 12, Byte: 11},
+						},
+					},
+				},
+			}),
+		},
+		{
+			"simple empty template with prefix trailing dot (wrapped)",
+			map[string]*schema.AttributeSchema{
+				"attr": {
+					Constraint: schema.AnyExpression{
+						OfType: cty.String,
+					},
+				},
+			},
+			reference.Targets{
+				{
+					Addr: lang.Address{
+						lang.RootStep{Name: "var"},
+						lang.AttrStep{Name: "bar"},
+					},
+					RangePtr: &hcl.Range{
+						Filename: "variables.tf",
+						Start:    hcl.Pos{Line: 2, Column: 1, Byte: 17},
+						End:      hcl.Pos{Line: 2, Column: 3, Byte: 19},
+					},
+					Type: cty.String,
+				},
+			},
+			`attr = "${var.}"
+`,
+			hcl.Pos{Line: 1, Column: 15, Byte: 14},
+			lang.CompleteCandidates([]lang.Candidate{
+				{
+					Label:  "var.bar",
+					Detail: "string",
+					Kind:   lang.ReferenceCandidateKind,
+					TextEdit: lang.TextEdit{
+						NewText: "var.bar",
+						Snippet: "var.bar",
+						Range: hcl.Range{
+							Filename: "test.tf",
+							Start:    hcl.Pos{Line: 1, Column: 11, Byte: 10},
+							End:      hcl.Pos{Line: 1, Column: 15, Byte: 14},
+						},
+					},
+				},
+			}),
+		},
 		{
 			"multi line template",
 			map[string]*schema.AttributeSchema{

diff --git a/decoder/expr_any_template.go b/decoder/expr_any_template.go
@@ -54,13 +54,26 @@ func (a Any) completeTemplateExprAtPos(ctx context.Context, pos hcl.Pos) ([]lang
 
 		return candidates, false
 	case *hclsyntax.TemplateWrapExpr:
-		if eType.Wrapped.Range().ContainsPos(pos) {
+		if eType.Wrapped.Range().ContainsPos(pos) || eType.Wrapped.Range().End.Byte == pos.Byte {
 			cons := schema.AnyExpression{
 				OfType: cty.String,
 			}
 			return newExpression(a.pathCtx, eType.Wrapped, cons).CompletionAtPos(ctx, pos), true
 		}
 
+		// Trailing dot may be ignored by the parser so we attempt to recover it
+		if pos.Byte-eType.Wrapped.Range().End.Byte == 1 {
+			fileBytes := a.pathCtx.Files[eType.Wrapped.Range().Filename].Bytes
+			trailingRune := fileBytes[eType.Wrapped.Range().End.Byte:pos.Byte][0]
+
+			if trailingRune == '.' {
+				cons := schema.AnyExpression{
+					OfType: cty.String,
+				}
+				return newExpression(a.pathCtx, eType.Wrapped, cons).CompletionAtPos(ctx, pos), true
+			}
+		}
+
 		return candidates, false
 	case *hclsyntax.TemplateJoinExpr:
 		// TODO: implement when support for expressions https://github.com/hashicorp/terraform-ls/issues/527 lands