package hcl
import (
"bufio"
"bytes"
"errors"
"fmt"
"io"
"sort"
wordwrap "github.com/mitchellh/go-wordwrap"
"github.com/zclconf/go-cty/cty"
)
type diagnosticTextWriter struct {
files map[string]*File
wr io.Writer
width uint
color bool
}
// NewDiagnosticTextWriter creates a DiagnosticWriter that writes diagnostics
// to the given writer as formatted text.
//
// It is designed to produce text appropriate to print in a monospaced font
// in a terminal of a particular width, or optionally with no width limit.
//
// The given width may be zero to disable word-wrapping of the detail text
// and truncation of source code snippets.
//
// If color is set to true, the output will include VT100 escape sequences to
// color-code the severity indicators. It is suggested to turn this off if
// the target writer is not a terminal.
func NewDiagnosticTextWriter(wr io.Writer, files map[string]*File, width uint, color bool) DiagnosticWriter {
return &diagnosticTextWriter{
files: files,
wr: wr,
width: width,
color: color,
}
}
func (w *diagnosticTextWriter) WriteDiagnostic(diag *Diagnostic) error {
if diag == nil {
return errors.New("nil diagnostic")
}
var colorCode, highlightCode, resetCode string
if w.color {
switch diag.Severity {
case DiagError:
colorCode = "\x1b[31m"
case DiagWarning:
colorCode = "\x1b[33m"
}
resetCode = "\x1b[0m"
highlightCode = "\x1b[1;4m"
}
var severityStr string
switch diag.Severity {
case DiagError:
severityStr = "Error"
case DiagWarning:
severityStr = "Warning"
default:
// should never happen
severityStr = "???????"
}
fmt.Fprintf(w.wr, "%s%s%s: %s\n\n", colorCode, severityStr, resetCode, diag.Summary)
if diag.Subject != nil {
snipRange := *diag.Subject
highlightRange := snipRange
if diag.Context != nil {
// Show enough of the source code to include both the subject
// and context ranges, which overlap in all reasonable
// situations.
snipRange = RangeOver(snipRange, *diag.Context)
}
// We can't illustrate an empty range, so we'll turn such ranges into
// single-character ranges, which might not be totally valid (may point
// off the end of a line, or off the end of the file) but are good
// enough for the bounds checks we do below.
if snipRange.Empty() {
snipRange.End.Byte++
snipRange.End.Column++
}
if highlightRange.Empty() {
highlightRange.End.Byte++
highlightRange.End.Column++
}
file := w.files[diag.Subject.Filename]
if file == nil || file.Bytes == nil {
fmt.Fprintf(w.wr, " on %s line %d:\n (source code not available)\n\n", diag.Subject.Filename, diag.Subject.Start.Line)
} else {
var contextLine string
if diag.Subject != nil {
contextLine = contextString(file, diag.Subject.Start.Byte)
if contextLine != "" {
contextLine = ", in " + contextLine
}
}
fmt.Fprintf(w.wr, " on %s line %d%s:\n", diag.Subject.Filename, diag.Subject.Start.Line, contextLine)
src := file.Bytes
sc := NewRangeScanner(src, diag.Subject.Filename, bufio.ScanLines)
for sc.Scan() {
lineRange := sc.Range()
if !lineRange.Overlaps(snipRange) {
continue
}
beforeRange, highlightedRange, afterRange := lineRange.PartitionAround(highlightRange)
if highlightedRange.Empty() {
fmt.Fprintf(w.wr, "%4d: %s\n", lineRange.Start.Line, sc.Bytes())
} else {
before := beforeRange.SliceBytes(src)
highlighted := highlightedRange.SliceBytes(src)
after := afterRange.SliceBytes(src)
fmt.Fprintf(
w.wr, "%4d: %s%s%s%s%s\n",
lineRange.Start.Line,
before,
highlightCode, highlighted, resetCode,
after,
)
}
}
w.wr.Write([]byte{'\n'})
}
if diag.Expression != nil && diag.EvalContext != nil {
// We will attempt to render the values for any variables
// referenced in the given expression as additional context, for
// situations where the same expression is evaluated multiple
// times in different scopes.
expr := diag.Expression
ctx := diag.EvalContext
vars := expr.Variables()
stmts := make([]string, 0, len(vars))
seen := make(map[string]struct{}, len(vars))
for _, traversal := range vars {
val, diags := traversal.TraverseAbs(ctx)
if diags.HasErrors() {
// Skip anything that generates errors, since we probably
// already have the same error in our diagnostics set
// already.
continue
}
traversalStr := w.traversalStr(traversal)
if _, exists := seen[traversalStr]; exists {
continue // don't show duplicates when the same variable is referenced multiple times
}
switch {
case !val.IsKnown():
// Can't say anything about this yet, then.
continue
case val.IsNull():
stmts = append(stmts, fmt.Sprintf("%s set to null", traversalStr))
default:
stmts = append(stmts, fmt.Sprintf("%s as %s", traversalStr, w.valueStr(val)))
}
seen[traversalStr] = struct{}{}
}
sort.Strings(stmts) // FIXME: Should maybe use a traversal-aware sort that can sort numeric indexes properly?
last := len(stmts) - 1
for i, stmt := range stmts {
switch i {
case 0:
w.wr.Write([]byte{'w', 'i', 't', 'h', ' '})
default:
w.wr.Write([]byte{' ', ' ', ' ', ' ', ' '})
}
w.wr.Write([]byte(stmt))
switch i {
case last:
w.wr.Write([]byte{'.', '\n', '\n'})
default:
w.wr.Write([]byte{',', '\n'})
}
}
}
}
if diag.Detail != "" {
detail := diag.Detail
if w.width != 0 {
detail = wordwrap.WrapString(detail, w.width)
}
fmt.Fprintf(w.wr, "%s\n\n", detail)
}
return nil
}
func (w *diagnosticTextWriter) WriteDiagnostics(diags Diagnostics) error {
for _, diag := range diags {
err := w.WriteDiagnostic(diag)
if err != nil {
return err
}
}
return nil
}
func (w *diagnosticTextWriter) traversalStr(traversal Traversal) string {
// This is a specialized subset of traversal rendering tailored to
// producing helpful contextual messages in diagnostics. It is not
// comprehensive nor intended to be used for other purposes.
var buf bytes.Buffer
for _, step := range traversal {
switch tStep := step.(type) {
case TraverseRoot:
buf.WriteString(tStep.Name)
case TraverseAttr:
buf.WriteByte('.')
buf.WriteString(tStep.Name)
case TraverseIndex:
buf.WriteByte('[')
if keyTy := tStep.Key.Type(); keyTy.IsPrimitiveType() {
buf.WriteString(w.valueStr(tStep.Key))
} else {
// We'll just use a placeholder for more complex values,
// since otherwise our result could grow ridiculously long.
buf.WriteString("...")
}
buf.WriteByte(']')
}
}
return buf.String()
}
func (w *diagnosticTextWriter) valueStr(val cty.Value) string {
// This is a specialized subset of value rendering tailored to producing
// helpful but concise messages in diagnostics. It is not comprehensive
// nor intended to be used for other purposes.
ty := val.Type()
switch {
case val.IsNull():
return "null"
case !val.IsKnown():
// Should never happen here because we should filter before we get
// in here, but we'll do something reasonable rather than panic.
return "(not yet known)"
case ty == cty.Bool:
if val.True() {
return "true"
}
return "false"
case ty == cty.Number:
bf := val.AsBigFloat()
return bf.Text('g', 10)
case ty == cty.String:
// Go string syntax is not exactly the same as HCL native string syntax,
// but we'll accept the minor edge-cases where this is different here
// for now, just to get something reasonable here.
return fmt.Sprintf("%q", val.AsString())
case ty.IsCollectionType() || ty.IsTupleType():
l := val.LengthInt()
switch l {
case 0:
return "empty " + ty.FriendlyName()
case 1:
return ty.FriendlyName() + " with 1 element"
default:
return fmt.Sprintf("%s with %d elements", ty.FriendlyName(), l)
}
case ty.IsObjectType():
atys := ty.AttributeTypes()
l := len(atys)
switch l {
case 0:
return "object with no attributes"
case 1:
var name string
for k := range atys {
name = k
}
return fmt.Sprintf("object with 1 attribute %q", name)
default:
return fmt.Sprintf("object with %d attributes", l)
}
default:
return ty.FriendlyName()
}
}
func contextString(file *File, offset int) string {
type contextStringer interface {
ContextString(offset int) string
}
if cser, ok := file.Nav.(contextStringer); ok {
return cser.ContextString(offset)
}
return ""
}
