app: define errors in a separate file

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/app/errors.go

@@ -0,0 +1,79 @@
+package app
+
+import (
+	"errors"
+
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+)
+
+// StateStoreError is returned for a failed state save
+type StateStoreError struct {
+	// whether inner function was called
+	Inner bool
+	// returned by the Save/Destroy method of [state.Cursor]
+	InnerErr error
+	// returned by the Do method of [state.Store]
+	DoErr error
+	// stores an arbitrary store operation error
+	OpErr error
+	// stores arbitrary errors
+	Err []error
+}
+
+// save saves arbitrary errors in [StateStoreError] once.
+func (e *StateStoreError) save(errs []error) {
+	if len(errs) == 0 || e.Err != nil {
+		panic("invalid call to save")
+	}
+	e.Err = errs
+}
+
+func (e *StateStoreError) equiv(a ...any) error {
+	if e.Inner && e.InnerErr == nil && e.DoErr == nil && e.OpErr == nil && errors.Join(e.Err...) == nil {
+		return nil
+	} else {
+		return fmsg.WrapErrorSuffix(e, a...)
+	}
+}
+
+func (e *StateStoreError) Error() string {
+	if e.Inner && e.InnerErr != nil {
+		return e.InnerErr.Error()
+	}
+	if e.DoErr != nil {
+		return e.DoErr.Error()
+	}
+	if e.OpErr != nil {
+		return e.OpErr.Error()
+	}
+	if err := errors.Join(e.Err...); err != nil {
+		return err.Error()
+	}
+
+	// equiv nullifies e for values where this is reached
+	panic("unreachable")
+}
+
+func (e *StateStoreError) Unwrap() (errs []error) {
+	errs = make([]error, 0, 3)
+	if e.InnerErr != nil {
+		errs = append(errs, e.InnerErr)
+	}
+	if e.DoErr != nil {
+		errs = append(errs, e.DoErr)
+	}
+	if e.OpErr != nil {
+		errs = append(errs, e.OpErr)
+	}
+	if err := errors.Join(e.Err...); err != nil {
+		errs = append(errs, err)
+	}
+	return
+}
+
+// A RevertCompoundError encapsulates errors returned by
+// the Revert method of [system.I].
+type RevertCompoundError interface {
+	Error() string
+	Unwrap() []error
+}

internal/app/process.go

@@ -211,75 +211,3 @@ func (seal *outcome) Run(ctx context.Context, rs *fst.RunState) error {
 
 	return earlyStoreErr.equiv("cannot save process state:")
 }
-
-// StateStoreError is returned for a failed state save
-type StateStoreError struct {
-	// whether inner function was called
-	Inner bool
-	// returned by the Save/Destroy method of [state.Cursor]
-	InnerErr error
-	// returned by the Do method of [state.Store]
-	DoErr error
-	// stores an arbitrary store operation error
-	OpErr error
-	// stores arbitrary errors
-	Err []error
-}
-
-// save saves arbitrary errors in [StateStoreError] once.
-func (e *StateStoreError) save(errs []error) {
-	if len(errs) == 0 || e.Err != nil {
-		panic("invalid call to save")
-	}
-	e.Err = errs
-}
-
-func (e *StateStoreError) equiv(a ...any) error {
-	if e.Inner && e.InnerErr == nil && e.DoErr == nil && e.OpErr == nil && errors.Join(e.Err...) == nil {
-		return nil
-	} else {
-		return fmsg.WrapErrorSuffix(e, a...)
-	}
-}
-
-func (e *StateStoreError) Error() string {
-	if e.Inner && e.InnerErr != nil {
-		return e.InnerErr.Error()
-	}
-	if e.DoErr != nil {
-		return e.DoErr.Error()
-	}
-	if e.OpErr != nil {
-		return e.OpErr.Error()
-	}
-	if err := errors.Join(e.Err...); err != nil {
-		return err.Error()
-	}
-
-	// equiv nullifies e for values where this is reached
-	panic("unreachable")
-}
-
-func (e *StateStoreError) Unwrap() (errs []error) {
-	errs = make([]error, 0, 3)
-	if e.InnerErr != nil {
-		errs = append(errs, e.InnerErr)
-	}
-	if e.DoErr != nil {
-		errs = append(errs, e.DoErr)
-	}
-	if e.OpErr != nil {
-		errs = append(errs, e.OpErr)
-	}
-	if err := errors.Join(e.Err...); err != nil {
-		errs = append(errs, err)
-	}
-	return
-}
-
-// A RevertCompoundError encapsulates errors returned by
-// the Revert method of [system.I].
-type RevertCompoundError interface {
-	Error() string
-	Unwrap() []error
-}