Check for duplicate keys in objects when building types from expressions

ext/typeexpr/get_type.go

@@ -6,9 +6,10 @@ package typeexpr
 import (
  "fmt"
 
- "github.com/hashicorp/hcl/v2"
  "github.com/zclconf/go-cty/cty"
  "github.com/zclconf/go-cty/cty/convert"
+
+ "github.com/hashicorp/hcl/v2"
 )
 
 const invalidTypeSummary = "Invalid type specification"
@@ -179,6 +180,18 @@ func getType(expr hcl.Expression, constraint, withDefaults bool) (cty.Type, *Def
  })
  continue
  }
+
+ if _, exists := atys[attrName]; exists {
+ diags = append(diags, &hcl.Diagnostic{
+ Severity: hcl.DiagError,
+ Summary: invalidTypeSummary,
+ Detail: "Object constructor map keys must be unique.",
+ Subject: attrDef.Key.Range().Ptr(),
+ Context: expr.Range().Ptr(),
+ })
+ continue
+ }
+
  atyExpr := attrDef.Value
 
  // the attribute type expression might be wrapped in the special

ext/typeexpr/get_type_test.go

@@ -10,10 +10,11 @@ import (
  "github.com/hashicorp/hcl/v2/gohcl"
 
  "github.com/google/go-cmp/cmp"
+ "github.com/zclconf/go-cty/cty"
+
  "github.com/hashicorp/hcl/v2"
  "github.com/hashicorp/hcl/v2/hclsyntax"
  "github.com/hashicorp/hcl/v2/json"
- "github.com/zclconf/go-cty/cty"
 )
 
 var (
@@ -700,6 +701,30 @@ func TestGetTypeDefaults(t *testing.T) {
  nil,
  `Optional attribute modifier expects at most two arguments: the attribute type, and a default value.`,
  },
+
+ // Duplicate arguments.
+ {
+ `map(object({operations=optional(list(string), []),type=optional(string, "ABC"),type=optional(number)}))`,
+ &Defaults{
+ Type: cty.Map(cty.ObjectWithOptionalAttrs(map[string]cty.Type{
+ "operations": cty.List(cty.String),
+ "type": cty.String,
+ }, []string{"operations", "type"})),
+ Children: map[string]*Defaults{
+ "": {
+ Type: cty.ObjectWithOptionalAttrs(map[string]cty.Type{
+ "operations": cty.List(cty.String),
+ "type": cty.String,
+ }, []string{"operations", "type"}),
+ DefaultValues: map[string]cty.Value{
+ "operations": cty.ListValEmpty(cty.String),
+ "type": cty.StringVal("ABC"),
+ },
+ },
+ },
+ },
+ "Object constructor map keys must be unique.",
+ },
  }
 
  for _, test := range tests {