package format
import (
"bufio"
"bytes"
"fmt"
"sort"
"strings"
"github.com/hashicorp/hcl2/hcl"
"github.com/hashicorp/hcl2/hcled"
"github.com/hashicorp/hcl2/hclparse"
"github.com/hashicorp/terraform/tfdiags"
"github.com/mitchellh/colorstring"
wordwrap "github.com/mitchellh/go-wordwrap"
"github.com/zclconf/go-cty/cty"
)
// Diagnostic formats a single diagnostic message.
//
// The width argument specifies at what column the diagnostic messages will
// be wrapped. If set to zero, messages will not be wrapped by this function
// at all. Although the long-form text parts of the message are wrapped,
// not all aspects of the message are guaranteed to fit within the specified
// terminal width.
func Diagnostic(diag tfdiags.Diagnostic, sources map[string][]byte, color *colorstring.Colorize, width int) string {
if diag == nil {
// No good reason to pass a nil diagnostic in here...
return ""
}
var buf bytes.Buffer
switch diag.Severity() {
case tfdiags.Error:
buf.WriteString(color.Color("\n[bold][red]Error: [reset]"))
case tfdiags.Warning:
buf.WriteString(color.Color("\n[bold][yellow]Warning: [reset]"))
default:
// Clear out any coloring that might be applied by Terraform's UI helper,
// so our result is not context-sensitive.
buf.WriteString(color.Color("\n[reset]"))
}
desc := diag.Description()
sourceRefs := diag.Source()
// We don't wrap the summary, since we expect it to be terse, and since
// this is where we put the text of a native Go error it may not always
// be pure text that lends itself well to word-wrapping.
fmt.Fprintf(&buf, color.Color("[bold]%s[reset]\n\n"), desc.Summary)
if sourceRefs.Subject != nil {
// We'll borrow HCL's range implementation here, because it has some
// handy features to help us produce a nice source code snippet.
highlightRange := sourceRefs.Subject.ToHCL()
snippetRange := highlightRange
if sourceRefs.Context != nil {
snippetRange = sourceRefs.Context.ToHCL()
}
// Make sure the snippet includes the highlight. This should be true
// for any reasonable diagnostic, but we'll make sure.
snippetRange = hcl.RangeOver(snippetRange, highlightRange)
if snippetRange.Empty() {
snippetRange.End.Byte++
snippetRange.End.Column++
}
if highlightRange.Empty() {
highlightRange.End.Byte++
highlightRange.End.Column++
}
var src []byte
if sources != nil {
src = sources[snippetRange.Filename]
}
if src == nil {
// This should generally not happen, as long as sources are always
// loaded through the main loader. We may load things in other
// ways in weird cases, so we'll tolerate it at the expense of
// a not-so-helpful error message.
fmt.Fprintf(&buf, " on %s line %d:\n (source code not available)\n", highlightRange.Filename, highlightRange.Start.Line)
} else {
file, offset := parseRange(src, highlightRange)
headerRange := highlightRange
contextStr := hcled.ContextString(file, offset-1)
if contextStr != "" {
contextStr = ", in " + contextStr
}
fmt.Fprintf(&buf, " on %s line %d%s:\n", headerRange.Filename, headerRange.Start.Line, contextStr)
// Config snippet rendering
sc := hcl.NewRangeScanner(src, highlightRange.Filename, bufio.ScanLines)
for sc.Scan() {
lineRange := sc.Range()
if !lineRange.Overlaps(snippetRange) {
continue
}
beforeRange, highlightedRange, afterRange := lineRange.PartitionAround(highlightRange)
before := beforeRange.SliceBytes(src)
highlighted := highlightedRange.SliceBytes(src)
after := afterRange.SliceBytes(src)
fmt.Fprintf(
&buf, color.Color("%4d: %s[underline]%s[reset]%s\n"),
lineRange.Start.Line,
before, highlighted, after,
)
}
}
if fromExpr := diag.FromExpr(); fromExpr != nil {
// We may also be able to generate information about the dynamic
// values of relevant variables at the point of evaluation, then.
// This is particularly useful for expressions that get evaluated
// multiple times with different values, such as blocks using
// "count" and "for_each", or within "for" expressions.
expr := fromExpr.Expression
ctx := fromExpr.EvalContext
vars := expr.Variables()
stmts := make([]string, 0, len(vars))
seen := make(map[string]struct{}, len(vars))
Traversals:
for _, traversal := range vars {
for len(traversal) > 1 {
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.
traversal = traversal[:len(traversal)-1]
continue
}
traversalStr := traversalStr(traversal)
if _, exists := seen[traversalStr]; exists {
continue Traversals // 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 Traversals
case val.IsNull():
stmts = append(stmts, fmt.Sprintf(color.Color("[bold]%s[reset] is null"), traversalStr))
default:
stmts = append(stmts, fmt.Sprintf(color.Color("[bold]%s[reset] is %s"), traversalStr, compactValueStr(val)))
}
seen[traversalStr] = struct{}{}
}
}
sort.Strings(stmts) // FIXME: Should maybe use a traversal-aware sort that can sort numeric indexes properly?
if len(stmts) > 0 {
fmt.Fprint(&buf, color.Color(" [dark_gray]|----------------[reset]\n"))
}
for _, stmt := range stmts {
fmt.Fprintf(&buf, color.Color(" [dark_gray]|[reset] %s\n"), stmt)
}
}
buf.WriteByte('\n')
}
if desc.Detail != "" {
detail := desc.Detail
if width != 0 {
detail = wordwrap.WrapString(detail, uint(width))
}
fmt.Fprintf(&buf, "%s\n", detail)
}
return buf.String()
}
func parseRange(src []byte, rng hcl.Range) (*hcl.File, int) {
filename := rng.Filename
offset := rng.Start.Byte
// We need to re-parse here to get a *hcl.File we can interrogate. This
// is not awesome since we presumably already parsed the file earlier too,
// but this re-parsing is architecturally simpler than retaining all of
// the hcl.File objects and we only do this in the case of an error anyway
// so the overhead here is not a big problem.
parser := hclparse.NewParser()
var file *hcl.File
var diags hcl.Diagnostics
if strings.HasSuffix(filename, ".json") {
file, diags = parser.ParseJSON(src, filename)
} else {
file, diags = parser.ParseHCL(src, filename)
}
if diags.HasErrors() {
return file, offset
}
return file, offset
}
// traversalStr produces a representation of an HCL traversal that is compact,
// resembles HCL native syntax, and is suitable for display in the UI.
func traversalStr(traversal hcl.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 hcl.TraverseRoot:
buf.WriteString(tStep.Name)
case hcl.TraverseAttr:
buf.WriteByte('.')
buf.WriteString(tStep.Name)
case hcl.TraverseIndex:
buf.WriteByte('[')
if keyTy := tStep.Key.Type(); keyTy.IsPrimitiveType() {
buf.WriteString(compactValueStr(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()
}
// compactValueStr produces a compact, single-line summary of a given value
// that is suitable for display in the UI.
//
// For primitives it returns a full representation, while for more complex
// types it instead summarizes the type, size, etc to produce something
// that is hopefully still somewhat useful but not as verbose as a rendering
// of the entire data structure.
func compactValueStr(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()
}
}
