blob: b4d71bf3c8f3ec2084d4e709477aae7f071c396c [file] [log] [blame]
package tfdiags
import (
"bytes"
"fmt"
"path/filepath"
"sort"
"strings"
"github.com/hashicorp/errwrap"
multierror "github.com/hashicorp/go-multierror"
"github.com/hashicorp/hcl/v2"
)
// Diagnostics is a list of diagnostics. Diagnostics is intended to be used
// where a Go "error" might normally be used, allowing richer information
// to be conveyed (more context, support for warnings).
//
// A nil Diagnostics is a valid, empty diagnostics list, thus allowing
// heap allocation to be avoided in the common case where there are no
// diagnostics to report at all.
type Diagnostics []Diagnostic
// Append is the main interface for constructing Diagnostics lists, taking
// an existing list (which may be nil) and appending the new objects to it
// after normalizing them to be implementations of Diagnostic.
//
// The usual pattern for a function that natively "speaks" diagnostics is:
//
// // Create a nil Diagnostics at the start of the function
// var diags diag.Diagnostics
//
// // At later points, build on it if errors / warnings occur:
// foo, err := DoSomethingRisky()
// if err != nil {
// diags = diags.Append(err)
// }
//
// // Eventually return the result and diagnostics in place of error
// return result, diags
//
// Append accepts a variety of different diagnostic-like types, including
// native Go errors and HCL diagnostics. It also knows how to unwrap
// a multierror.Error into separate error diagnostics. It can be passed
// another Diagnostics to concatenate the two lists. If given something
// it cannot handle, this function will panic.
func (diags Diagnostics) Append(new ...interface{}) Diagnostics {
for _, item := range new {
if item == nil {
continue
}
switch ti := item.(type) {
case Diagnostic:
diags = append(diags, ti)
case Diagnostics:
diags = append(diags, ti...) // flatten
case diagnosticsAsError:
diags = diags.Append(ti.Diagnostics) // unwrap
case NonFatalError:
diags = diags.Append(ti.Diagnostics) // unwrap
case hcl.Diagnostics:
for _, hclDiag := range ti {
diags = append(diags, hclDiagnostic{hclDiag})
}
case *hcl.Diagnostic:
diags = append(diags, hclDiagnostic{ti})
case *multierror.Error:
for _, err := range ti.Errors {
diags = append(diags, nativeError{err})
}
case error:
switch {
case errwrap.ContainsType(ti, Diagnostics(nil)):
// If we have an errwrap wrapper with a Diagnostics hiding
// inside then we'll unpick it here to get access to the
// individual diagnostics.
diags = diags.Append(errwrap.GetType(ti, Diagnostics(nil)))
case errwrap.ContainsType(ti, hcl.Diagnostics(nil)):
// Likewise, if we have HCL diagnostics we'll unpick that too.
diags = diags.Append(errwrap.GetType(ti, hcl.Diagnostics(nil)))
default:
diags = append(diags, nativeError{ti})
}
default:
panic(fmt.Errorf("can't construct diagnostic(s) from %T", item))
}
}
// Given the above, we should never end up with a non-nil empty slice
// here, but we'll make sure of that so callers can rely on empty == nil
if len(diags) == 0 {
return nil
}
return diags
}
// HasErrors returns true if any of the diagnostics in the list have
// a severity of Error.
func (diags Diagnostics) HasErrors() bool {
for _, diag := range diags {
if diag.Severity() == Error {
return true
}
}
return false
}
// ForRPC returns a version of the receiver that has been simplified so that
// it is friendly to RPC protocols.
//
// Currently this means that it can be serialized with encoding/gob and
// subsequently re-inflated. It may later grow to include other serialization
// formats.
//
// Note that this loses information about the original objects used to
// construct the diagnostics, so e.g. the errwrap API will not work as
// expected on an error-wrapped Diagnostics that came from ForRPC.
func (diags Diagnostics) ForRPC() Diagnostics {
ret := make(Diagnostics, len(diags))
for i := range diags {
ret[i] = makeRPCFriendlyDiag(diags[i])
}
return ret
}
// Err flattens a diagnostics list into a single Go error, or to nil
// if the diagnostics list does not include any error-level diagnostics.
//
// This can be used to smuggle diagnostics through an API that deals in
// native errors, but unfortunately it will lose any warnings that aren't
// accompanied by at least one error since such APIs have no mechanism through
// which to report those.
//
// return result, diags.Error()
func (diags Diagnostics) Err() error {
if !diags.HasErrors() {
return nil
}
return diagnosticsAsError{diags}
}
// ErrWithWarnings is similar to Err except that it will also return a non-nil
// error if the receiver contains only warnings.
//
// In the warnings-only situation, the result is guaranteed to be of dynamic
// type NonFatalError, allowing diagnostics-aware callers to type-assert
// and unwrap it, treating it as non-fatal.
//
// This should be used only in contexts where the caller is able to recognize
// and handle NonFatalError. For normal callers that expect a lack of errors
// to be signaled by nil, use just Diagnostics.Err.
func (diags Diagnostics) ErrWithWarnings() error {
if len(diags) == 0 {
return nil
}
if diags.HasErrors() {
return diags.Err()
}
return NonFatalError{diags}
}
// NonFatalErr is similar to Err except that it always returns either nil
// (if there are no diagnostics at all) or NonFatalError.
//
// This allows diagnostics to be returned over an error return channel while
// being explicit that the diagnostics should not halt processing.
//
// This should be used only in contexts where the caller is able to recognize
// and handle NonFatalError. For normal callers that expect a lack of errors
// to be signaled by nil, use just Diagnostics.Err.
func (diags Diagnostics) NonFatalErr() error {
if len(diags) == 0 {
return nil
}
return NonFatalError{diags}
}
// Sort applies an ordering to the diagnostics in the receiver in-place.
//
// The ordering is: warnings before errors, sourceless before sourced,
// short source paths before long source paths, and then ordering by
// position within each file.
//
// Diagnostics that do not differ by any of these sortable characteristics
// will remain in the same relative order after this method returns.
func (diags Diagnostics) Sort() {
sort.Stable(sortDiagnostics(diags))
}
type diagnosticsAsError struct {
Diagnostics
}
func (dae diagnosticsAsError) Error() string {
diags := dae.Diagnostics
switch {
case len(diags) == 0:
// should never happen, since we don't create this wrapper if
// there are no diagnostics in the list.
return "no errors"
case len(diags) == 1:
desc := diags[0].Description()
if desc.Detail == "" {
return desc.Summary
}
return fmt.Sprintf("%s: %s", desc.Summary, desc.Detail)
default:
var ret bytes.Buffer
fmt.Fprintf(&ret, "%d problems:\n", len(diags))
for _, diag := range dae.Diagnostics {
desc := diag.Description()
if desc.Detail == "" {
fmt.Fprintf(&ret, "\n- %s", desc.Summary)
} else {
fmt.Fprintf(&ret, "\n- %s: %s", desc.Summary, desc.Detail)
}
}
return ret.String()
}
}
// WrappedErrors is an implementation of errwrap.Wrapper so that an error-wrapped
// diagnostics object can be picked apart by errwrap-aware code.
func (dae diagnosticsAsError) WrappedErrors() []error {
var errs []error
for _, diag := range dae.Diagnostics {
if wrapper, isErr := diag.(nativeError); isErr {
errs = append(errs, wrapper.err)
}
}
return errs
}
// NonFatalError is a special error type, returned by
// Diagnostics.ErrWithWarnings and Diagnostics.NonFatalErr,
// that indicates that the wrapped diagnostics should be treated as non-fatal.
// Callers can conditionally type-assert an error to this type in order to
// detect the non-fatal scenario and handle it in a different way.
type NonFatalError struct {
Diagnostics
}
func (woe NonFatalError) Error() string {
diags := woe.Diagnostics
switch {
case len(diags) == 0:
// should never happen, since we don't create this wrapper if
// there are no diagnostics in the list.
return "no errors or warnings"
case len(diags) == 1:
desc := diags[0].Description()
if desc.Detail == "" {
return desc.Summary
}
return fmt.Sprintf("%s: %s", desc.Summary, desc.Detail)
default:
var ret bytes.Buffer
if diags.HasErrors() {
fmt.Fprintf(&ret, "%d problems:\n", len(diags))
} else {
fmt.Fprintf(&ret, "%d warnings:\n", len(diags))
}
for _, diag := range woe.Diagnostics {
desc := diag.Description()
if desc.Detail == "" {
fmt.Fprintf(&ret, "\n- %s", desc.Summary)
} else {
fmt.Fprintf(&ret, "\n- %s: %s", desc.Summary, desc.Detail)
}
}
return ret.String()
}
}
// sortDiagnostics is an implementation of sort.Interface
type sortDiagnostics []Diagnostic
var _ sort.Interface = sortDiagnostics(nil)
func (sd sortDiagnostics) Len() int {
return len(sd)
}
func (sd sortDiagnostics) Less(i, j int) bool {
iD, jD := sd[i], sd[j]
iSev, jSev := iD.Severity(), jD.Severity()
iSrc, jSrc := iD.Source(), jD.Source()
switch {
case iSev != jSev:
return iSev == Warning
case (iSrc.Subject == nil) != (jSrc.Subject == nil):
return iSrc.Subject == nil
case iSrc.Subject != nil && *iSrc.Subject != *jSrc.Subject:
iSubj := iSrc.Subject
jSubj := jSrc.Subject
switch {
case iSubj.Filename != jSubj.Filename:
// Path with fewer segments goes first if they are different lengths
sep := string(filepath.Separator)
iCount := strings.Count(iSubj.Filename, sep)
jCount := strings.Count(jSubj.Filename, sep)
if iCount != jCount {
return iCount < jCount
}
return iSubj.Filename < jSubj.Filename
case iSubj.Start.Byte != jSubj.Start.Byte:
return iSubj.Start.Byte < jSubj.Start.Byte
case iSubj.End.Byte != jSubj.End.Byte:
return iSubj.End.Byte < jSubj.End.Byte
}
fallthrough
default:
// The remaining properties do not have a defined ordering, so
// we'll leave it unspecified. Since we use sort.Stable in
// the caller of this, the ordering of remaining items will
// be preserved.
return false
}
}
func (sd sortDiagnostics) Swap(i, j int) {
sd[i], sd[j] = sd[j], sd[i]
}