refactor: add errors package that wraps cockroachdb/errors (#112)

cockroachdb/errors gives us stack traces and information for end users
with WithHint().

The reason for the 'errors' wrapper package is so as not to spread a
third party dependency all over the code and make it easier to replace
should that ever become necessary. If the API of the internal 'errors'
keeps growing and becoming closer and closer to cockroachdb/errors then
at some point the internal package might be deleted.

In schema.resolvers.go it was necessary to import the packages as
'errors2' because otherwise the automated code generation kept
overriding it.

cleoc/cleoc/config.go

@@ -1,11 +1,12 @@
 package cleoc
 
 import (
-	"fmt"
 	"strings"
 
 	"github.com/adrg/xdg"
 	"github.com/spf13/viper"
+
+	"github.com/cleodora-forecasting/cleodora/cleoutils/errors"
 )
 
 const DefaultConfigFileName = "cleoc"
@@ -37,7 +38,7 @@ func (c *Config) LoadWithViper(v *viper.Viper) error {
 				// Note that ConfigFileNotFoundError is not returned when
 				// explicitly specifying a config path (--config), which should
 				// (and does) cause an error if it doesn't exist.
-				return fmt.Errorf("error reading config file: %w", err)
+				return errors.Newf("error reading config file: %w", err)
 			}
 		}
 	}

cleoc/cleoc/forecast.go

@@ -2,7 +2,6 @@ package cleoc
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"net/http"
 	"time"
@@ -11,20 +10,21 @@ import (
 	"github.com/hashicorp/go-multierror"
 
 	"github.com/cleodora-forecasting/cleodora/cleoc/gqclient"
+	"github.com/cleodora-forecasting/cleodora/cleoutils/errors"
 )
 
 // AddForecast creates a new forecast.
 // The incoming options opts are assumed to already have been validated.
 func (a *App) AddForecast(opts AddForecastOptions) error {
 	resolvesT, err := time.Parse(time.RFC3339, opts.Resolves)
 	if err != nil {
-		return fmt.Errorf("could not parse 'resolves': %w", err)
+		return errors.Newf("could not parse 'resolves': %w", err)
 	}
 	var closesT *time.Time
 	if opts.Closes != "" {
 		parsedTime, err := time.Parse(time.RFC3339, opts.Closes)
 		if err != nil {
-			return fmt.Errorf("could not parse 'closes': %w", err)
+			return errors.Newf("could not parse 'closes': %w", err)
 		}
 		closesT = &parsedTime
 	}
@@ -42,7 +42,7 @@ func (a *App) AddForecast(opts AddForecastOptions) error {
 
 	reqProbabilities, err := parseProbabilities(opts.Probabilities)
 	if err != nil {
-		return fmt.Errorf("error parsing probabilities: %w", err)
+		return errors.Newf("error parsing probabilities: %w", err)
 	}
 
 	estimate := gqclient.NewEstimate{
@@ -51,7 +51,7 @@ func (a *App) AddForecast(opts AddForecastOptions) error {
 	}
 	resp, err := gqclient.CreateForecast(ctx, client, forecast, estimate)
 	if err != nil {
-		return fmt.Errorf("error calling the API: %w", err)
+		return errors.Newf("error calling the API: %w", err)
 	}
 	_, err = fmt.Fprint(a.Out, resp.CreateForecast.Id+"\n")
 	if err != nil {
@@ -141,7 +141,7 @@ func (opts *AddForecastOptions) Validate() error {
 	if sumProbabilities != 100 {
 		validationErr = multierror.Append(
 			validationErr,
-			fmt.Errorf(
+			errors.Newf(
 				"all probabilities must add up to 100 (here only %v)",
 				sumProbabilities,
 			),

cleosrv/cleosrv/cleosrv.go

@@ -18,6 +18,7 @@ import (
 	"github.com/cleodora-forecasting/cleodora/cleosrv/graph"
 	"github.com/cleodora-forecasting/cleodora/cleosrv/graph/generated"
 	"github.com/cleodora-forecasting/cleodora/cleoutils"
+	"github.com/cleodora-forecasting/cleodora/cleoutils/errors"
 )
 
 type App struct {
@@ -56,7 +57,7 @@ Listening on: %s
 
 	err := os.MkdirAll(filepath.Dir(a.Config.Database), 0770)
 	if err != nil {
-		return fmt.Errorf("error making directories for database %v: %w", a.Config.Database, err)
+		return errors.Newf("error making directories for database %v: %w", a.Config.Database, err)
 	}
 
 	router := chi.NewRouter()
@@ -103,7 +104,7 @@ func (a *App) InitDB() (*gorm.DB, error) {
 
 	err = migrateDB(db)
 	if err != nil {
-		return nil, fmt.Errorf("migrating data: %w", err)
+		return nil, errors.Newf("migrating data: %w", err)
 	}
 
 	return db, nil
@@ -121,7 +122,7 @@ func migrateDB(db *gorm.DB) error {
 		return tx.Migrator().AutoMigrate(&Migrations{})
 	})
 	if err != nil {
-		return fmt.Errorf("auto migrating 'migrations' table: %w", err)
+		return errors.Newf("auto migrating 'migrations' table: %w", err)
 	}
 	// If the DB is completely new then we just insert all migrations as 'done'
 	// i.e. they are not really executed because the createDb() function is
@@ -130,7 +131,7 @@ func migrateDB(db *gorm.DB) error {
 		err := db.Transaction(func(tx *gorm.DB) error {
 			err := createDb(tx)
 			if err != nil {
-				return fmt.Errorf("creating tables: %w", err)
+				return errors.Newf("creating tables: %w", err)
 			}
 			// save all migrations as done in the DB, without executing the
 			// functions.
@@ -146,7 +147,7 @@ func migrateDB(db *gorm.DB) error {
 			}
 			ret := tx.Create(mEntries)
 			if ret.Error != nil {
-				return fmt.Errorf("storing migrations as done in DB: %w", ret.Error)
+				return errors.Newf("storing migrations as done in DB: %w", ret.Error)
 			}
 			return nil
 		})
@@ -157,7 +158,7 @@ func migrateDB(db *gorm.DB) error {
 		var count int64
 		ret := db.Model(&Migrations{}).Where("id = ?", m.ID).Count(&count)
 		if ret.Error != nil {
-			return fmt.Errorf("selecting migration %v: %w", m.ID, ret.Error)
+			return errors.Newf("selecting migration %v: %w", m.ID, ret.Error)
 		}
 		if count == 1 {
 			continue // migration already ran in the past
@@ -167,15 +168,15 @@ func migrateDB(db *gorm.DB) error {
 			if m.Up != nil {
 				err = m.Up(tx)
 				if err != nil {
-					return fmt.Errorf("running %v: %w", m.ID, err)
+					return errors.Newf("running %v: %w", m.ID, err)
 				}
 			}
 			ret = tx.Create(Migrations{
 				ID:      m.ID,
 				Applied: time.Now().UTC(),
 			})
 			if ret.Error != nil {
-				return fmt.Errorf("saving migration %v: %w", m.ID, ret.Error)
+				return errors.Newf("saving migration %v: %w", m.ID, ret.Error)
 			}
 			fmt.Printf("Finished DB migration '%v'\n", m.ID)
 			return nil
@@ -225,7 +226,7 @@ var dbMigrations = []dbMigration{
 			var forecasts []Forecast
 			ret := db.Find(&forecasts)
 			if ret.Error != nil {
-				return fmt.Errorf("getting forecasts: %w", ret.Error)
+				return errors.Newf("getting forecasts: %w", ret.Error)
 			}
 			for _, f := range forecasts {
 				f.Created = f.Created.UTC()
@@ -252,7 +253,7 @@ var dbMigrations = []dbMigration{
 				}
 				ret = db.Save(f)
 				if ret.Error != nil {
-					return fmt.Errorf("saving %v: %w", f.ID, ret.Error)
+					return errors.Newf("saving %v: %w", f.ID, ret.Error)
 				}
 			}
 			return nil
@@ -268,14 +269,14 @@ var dbMigrations = []dbMigration{
 			var estimates []Estimate
 			ret := db.Find(&estimates)
 			if ret.Error != nil {
-				return fmt.Errorf("getting estimates: %w", ret.Error)
+				return errors.Newf("getting estimates: %w", ret.Error)
 			}
 			for _, e := range estimates {
 				e.Created = e.Created.UTC()
 				e.CreatedAt = e.CreatedAt.UTC()
 				ret = db.Save(e)
 				if ret.Error != nil {
-					return fmt.Errorf("saving %v: %w", e.ID, ret.Error)
+					return errors.Newf("saving %v: %w", e.ID, ret.Error)
 				}
 			}
 			return nil
@@ -290,13 +291,13 @@ var dbMigrations = []dbMigration{
 			var outcomes []Outcome
 			ret := db.Find(&outcomes)
 			if ret.Error != nil {
-				return fmt.Errorf("getting outcomes: %w", ret.Error)
+				return errors.Newf("getting outcomes: %w", ret.Error)
 			}
 			for _, o := range outcomes {
 				o.CreatedAt = o.CreatedAt.UTC()
 				ret = db.Save(o)
 				if ret.Error != nil {
-					return fmt.Errorf("saving %v: %w", o.ID, ret.Error)
+					return errors.Newf("saving %v: %w", o.ID, ret.Error)
 				}
 			}
 			return nil
@@ -311,13 +312,13 @@ var dbMigrations = []dbMigration{
 			var probabilities []Probability
 			ret := db.Find(&probabilities)
 			if ret.Error != nil {
-				return fmt.Errorf("getting probabilities: %w", ret.Error)
+				return errors.Newf("getting probabilities: %w", ret.Error)
 			}
 			for _, p := range probabilities {
 				p.CreatedAt = p.CreatedAt.UTC()
 				ret = db.Save(p)
 				if ret.Error != nil {
-					return fmt.Errorf("saving %v: %w", p.ID, ret.Error)
+					return errors.Newf("saving %v: %w", p.ID, ret.Error)
 				}
 			}
 			return nil
@@ -366,15 +367,15 @@ var dbMigrations = []dbMigration{
 				Scan(&estimateBriers)
 
 			if ret.Error != nil {
-				return fmt.Errorf("error calculating brier score: %w", ret.Error)
+				return errors.Newf("error calculating brier score: %w", ret.Error)
 			}
 
 			for _, r := range estimateBriers {
 				ret := db.Model(&dbmodel.Estimate{}).
 					Where("id = ?", r.ID).
 					Update("brier_score", r.Brier)
 				if ret.Error != nil {
-					return fmt.Errorf("error updating brier score: %w", ret.Error)
+					return errors.Newf("error updating brier score: %w", ret.Error)
 				}
 			}
 

cleosrv/cleosrv/config.go

@@ -1,11 +1,12 @@
 package cleosrv
 
 import (
-	"fmt"
 	"strings"
 
 	"github.com/adrg/xdg"
 	"github.com/spf13/viper"
+
+	"github.com/cleodora-forecasting/cleodora/cleoutils/errors"
 )
 
 const DefaultConfigFileName = "cleosrv"
@@ -41,7 +42,7 @@ func (c *Config) LoadWithViper(v *viper.Viper) error {
 				// Note that ConfigFileNotFoundError is not returned when
 				// explicitly specifying a config path (--config), which should
 				// (and does) cause an error if it doesn't exist.
-				return fmt.Errorf("error reading config file: %w", err)
+				return errors.Newf("error reading config file: %w", err)
 			}
 		}
 	}

cleosrv/graph/resolver.go

@@ -4,7 +4,6 @@ package graph
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"html"
 	"strconv"
@@ -15,6 +14,7 @@ import (
 
 	"github.com/cleodora-forecasting/cleodora/cleosrv/dbmodel"
 	"github.com/cleodora-forecasting/cleodora/cleosrv/graph/model"
+	"github.com/cleodora-forecasting/cleodora/cleoutils/errors"
 )
 
 // This file will not be regenerated automatically.
@@ -55,12 +55,12 @@ func createEstimate(
 	estimate model.NewEstimate,
 ) (*model.Estimate, error) {
 	if err := validateNewEstimate(&estimate, false); err != nil {
-		return nil, fmt.Errorf("error validating NewEstimate: %w", err)
+		return nil, errors.Newf("error validating NewEstimate: %w", err)
 	}
 	forecast := dbmodel.Forecast{}
 	ret := tx.Where("id = ?", forecastID).First(&forecast)
 	if ret.Error != nil {
-		return nil, fmt.Errorf("error getting Forecast with ID %v: %w", forecastID, ret.Error)
+		return nil, errors.Newf("error getting Forecast with ID %v: %w", forecastID, ret.Error)
 	}
 
 	if estimate.Created.Before(forecast.Created) {
@@ -92,7 +92,7 @@ func createEstimate(
 	).Where("estimates.forecast_id = ?", forecastID).
 		Distinct().Pluck("outcomes.id", &validOutcomeIds)
 	if ret.Error != nil {
-		return nil, fmt.Errorf("error getting outcome IDs: %w", ret.Error)
+		return nil, errors.Newf("error getting outcome IDs: %w", ret.Error)
 	}
 
 	var submittedOutcomeIds []string
@@ -102,20 +102,20 @@ func createEstimate(
 
 	invalidOutcomeIds := stringSetDiff(submittedOutcomeIds, validOutcomeIds)
 	if len(invalidOutcomeIds) > 0 {
-		return nil, fmt.Errorf("invalid Outcome IDs: %v", invalidOutcomeIds)
+		return nil, errors.Newf("invalid Outcome IDs: %v", invalidOutcomeIds)
 	}
 
 	missingOutcomeIds := stringSetDiff(validOutcomeIds, submittedOutcomeIds)
 	if len(missingOutcomeIds) > 0 {
-		return nil, fmt.Errorf("missing Outcome IDs: %v", missingOutcomeIds)
+		return nil, errors.Newf("missing Outcome IDs: %v", missingOutcomeIds)
 	}
 
 	var probabilities []dbmodel.Probability
 
 	for _, p := range estimate.Probabilities {
 		outcomeID, err := strconv.ParseUint(*p.OutcomeID, 10, 64)
 		if err != nil {
-			return nil, fmt.Errorf("can't parse %v as uint: %w", outcomeID, err)
+			return nil, errors.Newf("can't parse %v as uint: %w", outcomeID, err)
 		}
 		probabilities = append(
 			probabilities,
@@ -134,7 +134,7 @@ func createEstimate(
 
 	err := tx.Model(&forecast).Association("Estimates").Append(&dbEstimate)
 	if err != nil {
-		return nil, fmt.Errorf("error creating Estimate: %w", err)
+		return nil, errors.Newf("error creating Estimate: %w", err)
 	}
 
 	return convertEstimateDBToGQL(dbEstimate), nil
@@ -192,7 +192,7 @@ func validateNewForecast(forecast *model.NewForecast) error {
 		if forecast.Closes.After(forecast.Resolves) {
 			validationErr = multierror.Append(
 				validationErr,
-				fmt.Errorf(
+				errors.Newf(
 					"'Closes' can't be set to a later date than 'Resolves'. "+
 						"Closes is '%v'. Resolves is '%v'",
 					*forecast.Closes,
@@ -217,7 +217,7 @@ func validateNewForecast(forecast *model.NewForecast) error {
 	if forecast.Resolves.Before(*forecast.Created) {
 		validationErr = multierror.Append(
 			validationErr,
-			fmt.Errorf(
+			errors.Newf(
 				"'Resolves' can't be set to an earlier date than 'Created'. "+
 					"Resolves is '%v'. Created is '%v'",
 				forecast.Resolves,
@@ -275,7 +275,7 @@ func validateNewEstimate(estimate *model.NewEstimate, duringCreateForecast bool)
 				if _, ok := existingOutcomes[p.Outcome.Text]; ok {
 					validationErr = multierror.Append(
 						validationErr,
-						fmt.Errorf("outcome '%v' is a duplicate", p.Outcome.Text),
+						errors.Newf("outcome '%v' is a duplicate", p.Outcome.Text),
 					)
 				}
 				existingOutcomes[p.Outcome.Text] = true
@@ -302,15 +302,15 @@ func validateNewEstimate(estimate *model.NewEstimate, duringCreateForecast bool)
 		if p.Value < 0 || p.Value > 100 {
 			validationErr = multierror.Append(
 				validationErr,
-				fmt.Errorf("probabilities must be between 0 and 100, not %v", p.Value),
+				errors.Newf("probabilities must be between 0 and 100, not %v", p.Value),
 			)
 		}
 		sumProbabilities += p.Value
 	}
 	if sumProbabilities != 100 {
 		validationErr = multierror.Append(
 			validationErr,
-			fmt.Errorf("probabilities must add up to 100, not %v", sumProbabilities),
+			errors.Newf("probabilities must add up to 100, not %v", sumProbabilities),
 		)
 	}
 
@@ -320,7 +320,7 @@ func validateNewEstimate(estimate *model.NewEstimate, duringCreateForecast bool)
 		if estimate.Created.After(now) {
 			validationErr = multierror.Append(
 				validationErr,
-				fmt.Errorf(
+				errors.Newf(
 					"'created' can't be in the future: %v",
 					estimate.Created,
 				),