blob: d1e4faf59b37820d3563c31c15fbd96d8624d9ae [file] [log] [blame]
package json
import (
"fmt"
"io/ioutil"
"os"
"github.com/hashicorp/hcl/v2"
)
// Parse attempts to parse the given buffer as JSON and, if successful, returns
// a hcl.File for the HCL configuration represented by it.
//
// This is not a generic JSON parser. Instead, it deals only with the profile
// of JSON used to express HCL configuration.
//
// The returned file is valid only if the returned diagnostics returns false
// from its HasErrors method. If HasErrors returns true, the file represents
// the subset of data that was able to be parsed, which may be none.
func Parse(src []byte, filename string) (*hcl.File, hcl.Diagnostics) {
return ParseWithStartPos(src, filename, hcl.Pos{Byte: 0, Line: 1, Column: 1})
}
// ParseWithStartPos attempts to parse like json.Parse, but unlike json.Parse
// you can pass a start position of the given JSON as a hcl.Pos.
//
// In most cases json.Parse should be sufficient, but it can be useful for parsing
// a part of JSON with correct positions.
func ParseWithStartPos(src []byte, filename string, start hcl.Pos) (*hcl.File, hcl.Diagnostics) {
rootNode, diags := parseFileContent(src, filename, start)
switch rootNode.(type) {
case *objectVal, *arrayVal:
// okay
default:
diags = diags.Append(&hcl.Diagnostic{
Severity: hcl.DiagError,
Summary: "Root value must be object",
Detail: "The root value in a JSON-based configuration must be either a JSON object or a JSON array of objects.",
Subject: rootNode.StartRange().Ptr(),
})
// Since we've already produced an error message for this being
// invalid, we'll return an empty placeholder here so that trying to
// extract content from our root body won't produce a redundant
// error saying the same thing again in more general terms.
fakePos := hcl.Pos{
Byte: 0,
Line: 1,
Column: 1,
}
fakeRange := hcl.Range{
Filename: filename,
Start: fakePos,
End: fakePos,
}
rootNode = &objectVal{
Attrs: []*objectAttr{},
SrcRange: fakeRange,
OpenRange: fakeRange,
}
}
file := &hcl.File{
Body: &body{
val: rootNode,
},
Bytes: src,
Nav: navigation{rootNode},
}
return file, diags
}
// ParseExpression parses the given buffer as a standalone JSON expression,
// returning it as an instance of Expression.
func ParseExpression(src []byte, filename string) (hcl.Expression, hcl.Diagnostics) {
return ParseExpressionWithStartPos(src, filename, hcl.Pos{Byte: 0, Line: 1, Column: 1})
}
// ParseExpressionWithStartPos parses like json.ParseExpression, but unlike
// json.ParseExpression you can pass a start position of the given JSON
// expression as a hcl.Pos.
func ParseExpressionWithStartPos(src []byte, filename string, start hcl.Pos) (hcl.Expression, hcl.Diagnostics) {
node, diags := parseExpression(src, filename, start)
return &expression{src: node}, diags
}
// ParseFile is a convenience wrapper around Parse that first attempts to load
// data from the given filename, passing the result to Parse if successful.
//
// If the file cannot be read, an error diagnostic with nil context is returned.
func ParseFile(filename string) (*hcl.File, hcl.Diagnostics) {
f, err := os.Open(filename)
if err != nil {
return nil, hcl.Diagnostics{
{
Severity: hcl.DiagError,
Summary: "Failed to open file",
Detail: fmt.Sprintf("The file %q could not be opened.", filename),
},
}
}
defer f.Close()
src, err := ioutil.ReadAll(f)
if err != nil {
return nil, hcl.Diagnostics{
{
Severity: hcl.DiagError,
Summary: "Failed to read file",
Detail: fmt.Sprintf("The file %q was opened, but an error occured while reading it.", filename),
},
}
}
return Parse(src, filename)
}