github.com/terramate-io/tf@v0.0.0-20230830114523-fce866b4dfcd/lang/blocktoattr/variables.go (about)

     1  // Copyright (c) HashiCorp, Inc.
     2  // SPDX-License-Identifier: MPL-2.0
     3  
     4  package blocktoattr
     5  
     6  import (
     7  	"github.com/hashicorp/hcl/v2"
     8  	"github.com/hashicorp/hcl/v2/ext/dynblock"
     9  	"github.com/hashicorp/hcl/v2/hcldec"
    10  	"github.com/terramate-io/tf/configs/configschema"
    11  )
    12  
    13  // ExpandedVariables finds all of the global variables referenced in the
    14  // given body with the given schema while taking into account the possibilities
    15  // both of "dynamic" blocks being expanded and the possibility of certain
    16  // attributes being written instead as nested blocks as allowed by the
    17  // FixUpBlockAttrs function.
    18  //
    19  // This function exists to allow variables to be analyzed prior to dynamic
    20  // block expansion while also dealing with the fact that dynamic block expansion
    21  // might in turn produce nested blocks that are subject to FixUpBlockAttrs.
    22  //
    23  // This is intended as a drop-in replacement for dynblock.VariablesHCLDec,
    24  // which is itself a drop-in replacement for hcldec.Variables.
    25  func ExpandedVariables(body hcl.Body, schema *configschema.Block) []hcl.Traversal {
    26  	rootNode := dynblock.WalkVariables(body)
    27  	return walkVariables(rootNode, body, schema)
    28  }
    29  
    30  func walkVariables(node dynblock.WalkVariablesNode, body hcl.Body, schema *configschema.Block) []hcl.Traversal {
    31  	givenRawSchema := hcldec.ImpliedSchema(schema.DecoderSpec())
    32  	ambiguousNames := ambiguousNames(schema)
    33  	effectiveRawSchema := effectiveSchema(givenRawSchema, body, ambiguousNames, false)
    34  	vars, children := node.Visit(effectiveRawSchema)
    35  
    36  	for _, child := range children {
    37  		if blockS, exists := schema.BlockTypes[child.BlockTypeName]; exists {
    38  			vars = append(vars, walkVariables(child.Node, child.Body(), &blockS.Block)...)
    39  		} else if attrS, exists := schema.Attributes[child.BlockTypeName]; exists && attrS.Type.IsCollectionType() && attrS.Type.ElementType().IsObjectType() {
    40  			// ☝️Check for collection type before element type, because if this is a mis-placed reference,
    41  			// a panic here will prevent other useful diags from being elevated to show the user what to fix
    42  			synthSchema := SchemaForCtyElementType(attrS.Type.ElementType())
    43  			vars = append(vars, walkVariables(child.Node, child.Body(), synthSchema)...)
    44  		}
    45  	}
    46  
    47  	return vars
    48  }