Merge pull request #123 from coder/safe_vals

chore: fix panic on some string arguments

Author: Emyrk

extract/parameter.go

@@ -370,13 +370,11 @@ func nullableString(block *terraform.Block, key string) *string {
 	if attr == nil || attr.IsNil() {
 		return nil
 	}
-	val := attr.Value()
-	if val.Type() != cty.String {
+
+	str, ok := hclext.AsString(attr.Value())
+	if !ok {
 		return nil
 	}
-
-	//nolint:gocritic // string type asserted
-	str := val.AsString()
 	return &str
 }
 
@@ -385,13 +383,9 @@ func optionalString(block *terraform.Block, key string) string {
 	if attr == nil || attr.IsNil() {
 		return ""
 	}
-	val := attr.Value()
-	if !val.Type().Equals(cty.String) {
-		return ""
-	}
 
-	//nolint:gocritic // string type asserted
-	return val.AsString()
+	str, _ := hclext.AsString(attr.Value())
+	return str
 }
 
 func required(block *terraform.Block, keys ...string) hcl.Diagnostics {

hclext/asstring.go

@@ -0,0 +1,26 @@
+package hclext
+
+import "github.com/zclconf/go-cty/cty"
+
+func AsString(v cty.Value) (string, bool) {
+	if v.IsNull() || !v.IsKnown() {
+		return "", false
+	}
+
+	switch {
+	case v.Type().Equals(cty.String):
+		//nolint:gocritic // string type asserted
+		return v.AsString(), true
+	case v.Type().Equals(cty.Number):
+		// TODO: Float vs Int?
+		return v.AsBigFloat().String(), true
+	case v.Type().Equals(cty.Bool):
+		if v.True() {
+			return "true", true
+		}
+		return "false", true
+
+	}
+
+	return "", false
+}

types/value.go

@@ -7,6 +7,8 @@ import (
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hclsyntax"
 	"github.com/zclconf/go-cty/cty"
+
+	"github.com/coder/preview/hclext"
 )
 
 const (
@@ -86,20 +88,9 @@ func NullString() HCLString {
 // calling this function.
 func (s HCLString) AsString() string {
 	if s.Valid() && s.Value.IsKnown() {
-		switch {
-		case s.Value.Type().Equals(cty.String):
-			//nolint:gocritic // string type asserted
-			return s.Value.AsString()
-		case s.Value.Type().Equals(cty.Number):
-			// TODO: Float vs Int?
-			return s.Value.AsBigFloat().String()
-		case s.Value.Type().Equals(cty.Bool):
-			if s.Value.True() {
-				return "true"
-			}
-			return "false"
-		default:
-			// ?? What to do?
+		str, ok := hclext.AsString(s.Value)
+		if ok {
+			return str
 		}
 	}