Merge pull request hashicorp#476 from hashicorp/jbardin/decode-unknow…

…n-dynblock

decode unknown dynamic blocks to ensure they are valid

ext/dynblock/expand_body.go

@@ -201,28 +201,14 @@ func (b *expandBody) expandBlocks(schema *hcl.BodySchema, rawBlocks hcl.Blocks,
  }
  }
  } else {
- // If our top-level iteration value isn't known then we're forced
- // to compromise since HCL doesn't have any concept of an
- // "unknown block". In this case then, we'll produce a single
- // dynamic block with the iterator values set to DynamicVal,
- // which at least makes the potential for a block visible
- // in our result, even though it's not represented in a fully-accurate
- // way.
+ // If our top-level iteration value isn't known then we
+ // substitute an unknownBody, which will cause the entire block
+ // to evaluate to an unknown value.
  i := b.iteration.MakeChild(spec.iteratorName, cty.DynamicVal, cty.DynamicVal)
  block, blockDiags := spec.newBlock(i, b.forEachCtx)
  diags = append(diags, blockDiags...)
  if block != nil {
- block.Body = b.expandChild(block.Body, i)
-
- // We additionally force all of the leaf attribute values
- // in the result to be unknown so the calling application
- // can, if necessary, use that as a heuristic to detect
- // when a single nested block might be standing in for
- // multiple blocks yet to be expanded. This retains the
- // structure of the generated body but forces all of its
- // leaf attribute values to be unknown.
- block.Body = unknownBody{block.Body}
-
+ block.Body = unknownBody{b.expandChild(block.Body, i)}
  blocks = append(blocks, block)
  }
  }

ext/dynblock/expand_body_test.go

@@ -1,6 +1,7 @@
 package dynblock
 
 import (
+ "strings"
  "testing"
 
  "github.com/hashicorp/hcl/v2"
@@ -441,6 +442,28 @@ func TestExpandUnknownBodies(t *testing.T) {
  },
  }),
  },
+ {
+ Type: "dynamic",
+ Labels: []string{"invalid_list"},
+ LabelRanges: []hcl.Range{hcl.Range{}},
+ Body: hcltest.MockBody(&hcl.BodyContent{
+ Attributes: hcltest.MockAttrs(map[string]hcl.Expression{
+ "for_each": hcltest.MockExprLiteral(cty.UnknownVal(cty.Map(cty.String))),
+ }),
+ Blocks: hcl.Blocks{
+ {
+ Type: "content",
+ Body: hcltest.MockBody(&hcl.BodyContent{
+ Attributes: hcltest.MockAttrs(map[string]hcl.Expression{
+ "val": hcltest.MockExprTraversalSrc("each.value"),
+ // unexpected attributes should still produce an error
+ "invalid": hcltest.MockExprLiteral(cty.StringVal("static")),
+ }),
+ }),
+ },
+ },
+ }),
+ },
  },
  }
 
@@ -574,4 +597,27 @@ func TestExpandUnknownBodies(t *testing.T) {
  }
  })
 
+ t.Run("DecodeInvalidList", func(t *testing.T) {
+ decSpec := &hcldec.BlockListSpec{
+ TypeName: "invalid_list",
+ Nested: &hcldec.ObjectSpec{
+ "val": &hcldec.AttrSpec{
+ Name: "val",
+ Type: cty.String,
+ },
+ },
+ }
+
+ _, _, diags := hcldec.PartialDecode(dynBody, decSpec, nil)
+ if len(diags) != 1 {
+ t.Error("expected 1 extraneous argument")
+ }
+
+ want := `Mock body has extraneous argument "invalid"`
+
+ if !strings.Contains(diags.Error(), want) {
+ t.Errorf("unexpected diagnostics: %v", diags)
+ }
+ })
+
 }

hcldec/spec.go

@@ -468,6 +468,9 @@ func (s *BlockListSpec) decode(content *hcl.BodyContent, blockLabels []blockLabe
  continue
  }
 
+ val, _, childDiags := decode(childBlock.Body, labelsForBlock(childBlock), ctx, s.Nested, false)
+ diags = append(diags, childDiags...)
+
  if u, ok := childBlock.Body.(UnknownBody); ok {
  if u.Unknown() {
  // If any block Body is unknown, then the entire block value
@@ -476,8 +479,6 @@ func (s *BlockListSpec) decode(content *hcl.BodyContent, blockLabels []blockLabe
  }
  }
 
- val, _, childDiags := decode(childBlock.Body, labelsForBlock(childBlock), ctx, s.Nested, false)
- diags = append(diags, childDiags...)
  elems = append(elems, val)
  sourceRanges = append(sourceRanges, sourceRange(childBlock.Body, labelsForBlock(childBlock), s.Nested))
  }
@@ -629,6 +630,9 @@ func (s *BlockTupleSpec) decode(content *hcl.BodyContent, blockLabels []blockLab
  continue
  }
 
+ val, _, childDiags := decode(childBlock.Body, labelsForBlock(childBlock), ctx, s.Nested, false)
+ diags = append(diags, childDiags...)
+
  if u, ok := childBlock.Body.(UnknownBody); ok {
  if u.Unknown() {
  // If any block Body is unknown, then the entire block value
@@ -637,8 +641,6 @@ func (s *BlockTupleSpec) decode(content *hcl.BodyContent, blockLabels []blockLab
  }
  }
 
- val, _, childDiags := decode(childBlock.Body, labelsForBlock(childBlock), ctx, s.Nested, false)
- diags = append(diags, childDiags...)
  elems = append(elems, val)
  sourceRanges = append(sourceRanges, sourceRange(childBlock.Body, labelsForBlock(childBlock), s.Nested))
  }
@@ -751,6 +753,9 @@ func (s *BlockSetSpec) decode(content *hcl.BodyContent, blockLabels []blockLabel
  continue
  }
 
+ val, _, childDiags := decode(childBlock.Body, labelsForBlock(childBlock), ctx, s.Nested, false)
+ diags = append(diags, childDiags...)
+
  if u, ok := childBlock.Body.(UnknownBody); ok {
  if u.Unknown() {
  // If any block Body is unknown, then the entire block value
@@ -759,8 +764,6 @@ func (s *BlockSetSpec) decode(content *hcl.BodyContent, blockLabels []blockLabel
  }
  }
 
- val, _, childDiags := decode(childBlock.Body, labelsForBlock(childBlock), ctx, s.Nested, false)
- diags = append(diags, childDiags...)
  elems = append(elems, val)
  sourceRanges = append(sourceRanges, sourceRange(childBlock.Body, labelsForBlock(childBlock), s.Nested))
  }