refactor: clean up errors

- Created generic Error types to remove the need to import the errors
  package.
- Used the generic Error types in place of the single use custom Error
  types that have no fields.
- Created new Error types where necessary.

PR: #50

internal/client/client.go

@@ -79,10 +79,9 @@ func (g *Client) DownloadMedia(url, path string) error {
 	defer response.Body.Close()
 
 	if response.StatusCode != http.StatusOK {
-		return fmt.Errorf(
-			"did not receive an OK response from the GoToSocial server: got %d",
-			response.StatusCode,
-		)
+		return BadStatusCodeError{
+			statusCode: response.StatusCode,
+		}
 	}
 
 	file, err := os.Create(path)

internal/client/errors.go

@@ -30,3 +30,22 @@ func (e ResponseError) Error() string {
 		e.Message,
 	)
 }
+
+type BadStatusCodeError struct {
+	statusCode int
+}
+
+func (e BadStatusCodeError) Error() string {
+	return fmt.Sprintf(
+		"did not receive an OK response from the GoToSocial server: got %d",
+		e.statusCode,
+	)
+}
+
+type Error struct {
+	message string
+}
+
+func (e Error) Error() string {
+	return e.message
+}

internal/client/token.go

@@ -3,15 +3,12 @@ package client
 import (
 	"bytes"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"net/http"
 
 	"codeflow.dananglin.me.uk/apollo/enbas/internal"
 )
 
-var errEmptyAccessToken = errors.New("received an empty access token")
-
 type tokenRequest struct {
 	RedirectURI  string `json:"redirect_uri"`
 	ClientID     string `json:"client_id"`
@@ -59,7 +56,7 @@ func (g *Client) UpdateToken(code string) error {
 	}
 
 	if response.AccessToken == "" {
-		return errEmptyAccessToken
+		return Error{"received an empty access token"}
 	}
 
 	g.Authentication.AccessToken = response.AccessToken

internal/executor/add.go

@@ -1,7 +1,6 @@
 package executor
 
 import (
-	"errors"
 	"fmt"
 
 	"codeflow.dananglin.me.uk/apollo/enbas/internal/client"
@@ -40,8 +39,8 @@ func (a *AddExecutor) addToList(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[a.resourceType]
 	if !ok {
 		return UnsupportedAddOperationError{
-			ResourceType:      a.resourceType,
-			AddToResourceType: a.toResourceType,
+			resourceType:      a.resourceType,
+			addToResourceType: a.toResourceType,
 		}
 	}
 
@@ -71,7 +70,7 @@ func (a *AddExecutor) addAccountsToList(gtsClient *client.Client) error {
 		}
 
 		if !relationship.Following {
-			return NotFollowingError{Account: accounts[ind].Acct}
+			return NotFollowingError{account: accounts[ind].Acct}
 		}
 
 		accountIDs[ind] = accounts[ind].ID
@@ -94,8 +93,8 @@ func (a *AddExecutor) addToAccount(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[a.resourceType]
 	if !ok {
 		return UnsupportedAddOperationError{
-			ResourceType:      a.resourceType,
-			AddToResourceType: a.toResourceType,
+			resourceType:      a.resourceType,
+			addToResourceType: a.toResourceType,
 		}
 	}
 
@@ -109,7 +108,7 @@ func (a *AddExecutor) addNoteToAccount(gtsClient *client.Client) error {
 	}
 
 	if a.content == "" {
-		return errors.New("please add content to the status that you want to create")
+		return Error{"please add content to the note you want to add"}
 	}
 
 	if err := gtsClient.SetPrivateNote(accountID, a.content); err != nil {
@@ -129,8 +128,8 @@ func (a *AddExecutor) addToBookmarks(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[a.resourceType]
 	if !ok {
 		return UnsupportedAddOperationError{
-			ResourceType:      a.resourceType,
-			AddToResourceType: a.toResourceType,
+			resourceType:      a.resourceType,
+			addToResourceType: a.toResourceType,
 		}
 	}
 
@@ -166,8 +165,8 @@ func (a *AddExecutor) addToStatus(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[a.resourceType]
 	if !ok {
 		return UnsupportedAddOperationError{
-			ResourceType:      a.resourceType,
-			AddToResourceType: a.toResourceType,
+			resourceType:      a.resourceType,
+			addToResourceType: a.toResourceType,
 		}
 	}
 
@@ -196,7 +195,7 @@ func (a *AddExecutor) addBoostToStatus(gtsClient *client.Client) error {
 
 func (a *AddExecutor) addVoteToStatus(gtsClient *client.Client) error {
 	if a.votes.Empty() {
-		return NoVotesError{}
+		return Error{"please add your vote(s) to the poll"}
 	}
 
 	status, err := gtsClient.GetStatus(a.statusID)
@@ -205,15 +204,15 @@ func (a *AddExecutor) addVoteToStatus(gtsClient *client.Client) error {
 	}
 
 	if status.Poll == nil {
-		return NoPollInStatusError{}
+		return Error{"this status does not have a poll"}
 	}
 
 	if status.Poll.Expired {
-		return PollClosedError{}
+		return Error{"this poll is closed"}
 	}
 
 	if !status.Poll.Multiple && !a.votes.ExpectedLength(1) {
-		return MultipleChoiceError{}
+		return Error{"this poll does not allow multiple choices"}
 	}
 
 	myAccountID, err := getAccountID(gtsClient, true, nil)
@@ -222,7 +221,7 @@ func (a *AddExecutor) addVoteToStatus(gtsClient *client.Client) error {
 	}
 
 	if status.Account.ID == myAccountID {
-		return PollOwnerVoteError{}
+		return Error{"you cannot vote in your own poll"}
 	}
 
 	pollID := status.Poll.ID

internal/executor/create.go

@@ -1,7 +1,6 @@
 package executor
 
 import (
-	"errors"
 	"fmt"
 
 	"codeflow.dananglin.me.uk/apollo/enbas/internal/client"
@@ -72,27 +71,35 @@ func (c *CreateExecutor) createStatus(gtsClient *client.Client) error {
 	if !c.mediaFiles.Empty() {
 		descriptionsExists := false
 		focusValuesExists := false
-		expectedLength := len(c.mediaFiles)
-		mediaDescriptions := make([]string, expectedLength)
+		numMediaFiles := len(c.mediaFiles)
+		mediaDescriptions := make([]string, numMediaFiles)
 
 		if !c.mediaDescriptions.Empty() {
 			descriptionsExists = true
 
-			if !c.mediaDescriptions.ExpectedLength(expectedLength) {
-				return errors.New("the number of media descriptions does not match the number of media files")
+			if !c.mediaDescriptions.ExpectedLength(numMediaFiles) {
+				return MismatchedNumMediaValuesError{
+					valueType:     "media descriptions",
+					numValues:     len(c.mediaDescriptions),
+					numMediaFiles: numMediaFiles,
+				}
 			}
 		}
 
 		if !c.mediaFocusValues.Empty() {
 			focusValuesExists = true
 
-			if !c.mediaFocusValues.ExpectedLength(expectedLength) {
-				return errors.New("the number of media focus values does not match the number of media files")
+			if !c.mediaFocusValues.ExpectedLength(numMediaFiles) {
+				return MismatchedNumMediaValuesError{
+					valueType:     "media focus values",
+					numValues:     len(c.mediaFocusValues),
+					numMediaFiles: numMediaFiles,
+				}
 			}
 		}
 
 		if descriptionsExists {
-			for ind := 0; ind < expectedLength; ind++ {
+			for ind := 0; ind < numMediaFiles; ind++ {
 				mediaDesc, err := utilities.ReadContents(c.mediaDescriptions[ind])
 				if err != nil {
 					return fmt.Errorf("unable to read the contents from %s: %w", c.mediaDescriptions[ind], err)
@@ -102,7 +109,7 @@ func (c *CreateExecutor) createStatus(gtsClient *client.Client) error {
 			}
 		}
 
-		for ind := 0; ind < expectedLength; ind++ {
+		for ind := 0; ind < numMediaFiles; ind++ {
 			var (
 				mediaFile   string
 				description string
@@ -133,7 +140,7 @@ func (c *CreateExecutor) createStatus(gtsClient *client.Client) error {
 	}
 
 	if c.content == "" && len(attachmentIDs) == 0 {
-		return errors.New("please add content to the status that you want to create")
+		return Error{"please add content to the status that you want to create"}
 	}
 
 	content, err := utilities.ReadContents(c.content)
@@ -144,7 +151,7 @@ func (c *CreateExecutor) createStatus(gtsClient *client.Client) error {
 	numAttachmentIDs := len(attachmentIDs)
 
 	if c.addPoll && numAttachmentIDs > 0 {
-		return fmt.Errorf("attaching media to a poll is not allowed")
+		return Error{"attaching media to a poll is not allowed"}
 	}
 
 	preferences, err := gtsClient.GetUserPreferences()
@@ -202,7 +209,7 @@ func (c *CreateExecutor) createStatus(gtsClient *client.Client) error {
 
 	if c.addPoll {
 		if len(c.pollOptions) == 0 {
-			return NoPollOptionError{}
+			return Error{"no options were provided for this poll"}
 		}
 
 		poll := client.CreateStatusPollForm{
@@ -227,28 +234,33 @@ func (c *CreateExecutor) createStatus(gtsClient *client.Client) error {
 
 func (c *CreateExecutor) createMediaAttachment(gtsClient *client.Client) error {
 	expectedNumValues := 1
+
 	if !c.mediaFiles.ExpectedLength(expectedNumValues) {
-		return fmt.Errorf(
-			"received an unexpected number of media files: want %d",
-			expectedNumValues,
-		)
+		return UnexpectedNumValuesError{
+			name:     "media files",
+			expected: expectedNumValues,
+			actual:   len(c.mediaFiles),
+		}
 	}
 
 	description := ""
 	if !c.mediaDescriptions.Empty() {
 		if !c.mediaDescriptions.ExpectedLength(expectedNumValues) {
-			return fmt.Errorf(
-				"received an unexpected number of media descriptions: want %d",
-				expectedNumValues,
-			)
+			return UnexpectedNumValuesError{
+				name:     "media descriptions",
+				expected: expectedNumValues,
+				actual:   len(c.mediaDescriptions),
+			}
 		}
 
 		var err error
+
 		description, err = utilities.ReadContents(c.mediaDescriptions[0])
 		if err != nil {
 			return fmt.Errorf(
 				"unable to read the contents from %s: %w",
 				c.mediaDescriptions[0],
+				err,
 			)
 		}
 	}
@@ -256,11 +268,13 @@ func (c *CreateExecutor) createMediaAttachment(gtsClient *client.Client) error {
 	focus := ""
 	if !c.mediaFocusValues.Empty() {
 		if !c.mediaFocusValues.ExpectedLength(expectedNumValues) {
-			return fmt.Errorf(
-				"received an unexpected number of media focus values: want %d",
-				expectedNumValues,
-			)
+			return UnexpectedNumValuesError{
+				name:     "media focus values",
+				expected: expectedNumValues,
+				actual:   len(c.mediaFocusValues),
+			}
 		}
+
 		focus = c.mediaFocusValues[0]
 	}
 

internal/executor/delete.go

@@ -1,7 +1,6 @@
 package executor
 
 import (
-	"errors"
 	"fmt"
 	"path/filepath"
 
@@ -62,7 +61,7 @@ func (d *DeleteExecutor) deleteStatus(gtsClient *client.Client) error {
 	}
 
 	if status.Account.ID != myAccountID {
-		return errors.New("unable to delete the status because the status does not belong to you")
+		return Error{"unable to delete the status because the status does not belong to you"}
 	}
 
 	text, err := gtsClient.DeleteStatus(d.statusID)

internal/executor/edit.go

@@ -69,10 +69,11 @@ func (e *EditExecutor) editMediaAttachment(gtsClient *client.Client) error {
 	expectedNumValues := 1
 
 	if !e.attachmentIDs.ExpectedLength(expectedNumValues) {
-		return fmt.Errorf(
-			"received an unexpected number of media attachment IDs: want %d",
-			expectedNumValues,
-		)
+		return UnexpectedNumValuesError{
+			name:     "media attachment IDs",
+			expected: expectedNumValues,
+			actual:   len(e.attachmentIDs),
+		}
 	}
 
 	attachment, err := gtsClient.GetMediaAttachment(e.attachmentIDs[0])
@@ -83,18 +84,21 @@ func (e *EditExecutor) editMediaAttachment(gtsClient *client.Client) error {
 	description := attachment.Description
 	if !e.mediaDescriptions.Empty() {
 		if !e.mediaDescriptions.ExpectedLength(expectedNumValues) {
-			return fmt.Errorf(
-				"received an unexpected number of media descriptions: want %d",
-				expectedNumValues,
-			)
+			return UnexpectedNumValuesError{
+				name:     "media description",
+				expected: expectedNumValues,
+				actual:   len(e.mediaDescriptions),
+			}
 		}
 
 		var err error
+
 		description, err = utilities.ReadContents(e.mediaDescriptions[0])
 		if err != nil {
 			return fmt.Errorf(
 				"unable to read the contents from %s: %w",
 				e.mediaDescriptions[0],
+				err,
 			)
 		}
 	}
@@ -102,11 +106,13 @@ func (e *EditExecutor) editMediaAttachment(gtsClient *client.Client) error {
 	focus := fmt.Sprintf("%f,%f", attachment.Meta.Focus.X, attachment.Meta.Focus.Y)
 	if !e.mediaFocusValues.Empty() {
 		if !e.mediaFocusValues.ExpectedLength(expectedNumValues) {
-			return fmt.Errorf(
-				"received an unexpected number of media focus values: want %d",
-				expectedNumValues,
-			)
+			return UnexpectedNumValuesError{
+				name:     "media focus values",
+				expected: expectedNumValues,
+				actual:   len(e.mediaFocusValues),
+			}
 		}
+
 		focus = e.mediaFocusValues[0]
 	}
 

internal/executor/errors.go

@@ -1,5 +1,15 @@
 package executor
 
+import "fmt"
+
+type Error struct {
+	message string
+}
+
+func (e Error) Error() string {
+	return e.message
+}
+
 type FlagNotSetError struct {
 	flagText string
 }
@@ -23,94 +33,87 @@ func (e NoAccountSpecifiedError) Error() string {
 }
 
 type UnsupportedAddOperationError struct {
-	ResourceType      string
-	AddToResourceType string
+	resourceType      string
+	addToResourceType string
 }
 
 func (e UnsupportedAddOperationError) Error() string {
 	return "adding '" +
-		e.ResourceType +
+		e.resourceType +
 		"' to '" +
-		e.AddToResourceType +
+		e.addToResourceType +
 		"' is not supported"
 }
 
 type UnsupportedRemoveOperationError struct {
-	ResourceType           string
-	RemoveFromResourceType string
+	resourceType           string
+	removeFromResourceType string
 }
 
 func (e UnsupportedRemoveOperationError) Error() string {
 	return "removing '" +
-		e.ResourceType +
+		e.resourceType +
 		"' from '" +
-		e.RemoveFromResourceType +
+		e.removeFromResourceType +
 		"' is not supported"
 }
 
 type UnsupportedShowOperationError struct {
-	ResourceType         string
-	ShowFromResourceType string
+	resourceType         string
+	showFromResourceType string
 }
 
 func (e UnsupportedShowOperationError) Error() string {
 	return "showing '" +
-		e.ResourceType +
+		e.resourceType +
 		"' from '" +
-		e.ShowFromResourceType +
+		e.showFromResourceType +
 		"' is not supported"
 }
 
 type UnknownCommandError struct {
-	Command string
+	command string
 }
 
 func (e UnknownCommandError) Error() string {
-	return "unknown command '" + e.Command + "'"
-}
-
-type PollClosedError struct{}
-
-func (e PollClosedError) Error() string {
-	return "this poll is closed"
-}
-
-type MultipleChoiceError struct{}
-
-func (e MultipleChoiceError) Error() string {
-	return "this poll does not allow multiple choices"
-}
-
-type NoPollOptionError struct{}
-
-func (e NoPollOptionError) Error() string {
-	return "no options were provided for this poll, please use the --" +
-		flagPollOption +
-		" flag to add options to the poll"
-}
-
-type NoVotesError struct{}
-
-func (e NoVotesError) Error() string {
-	return "no votes were made, please add your vote(s) using the --vote flag"
-}
-
-type NoPollInStatusError struct{}
-
-func (e NoPollInStatusError) Error() string {
-	return "this status does not have a poll"
-}
-
-type PollOwnerVoteError struct{}
-
-func (e PollOwnerVoteError) Error() string {
-	return "you cannot vote in your own poll"
+	return "unknown command '" + e.command + "'"
 }
 
 type NotFollowingError struct {
-	Account string
+	account string
 }
 
 func (e NotFollowingError) Error() string {
-	return "you are not following " + e.Account
+	return "you are not following " + e.account
+}
+
+type MismatchedNumMediaValuesError struct {
+	valueType     string
+	numValues     int
+	numMediaFiles int
+}
+
+func (e MismatchedNumMediaValuesError) Error() string {
+	return fmt.Sprintf(
+		"unexpected number of %s: received %d media files but got %d %s",
+		e.valueType,
+		e.numMediaFiles,
+		e.numValues,
+		e.valueType,
+	)
+}
+
+type UnexpectedNumValuesError struct {
+	name     string
+	actual   int
+	expected int
+}
+
+func (e UnexpectedNumValuesError) Error() string {
+	return fmt.Sprintf(
+		"received an unexpected number of %s: received %d, expected %d",
+		e.name,
+		e.actual,
+		e.expected,
+	)
 }

internal/executor/execute.go

@@ -145,7 +145,7 @@ func execute(
 
 	exe, ok := executorMap[command]
 	if !ok {
-		return UnknownCommandError{Command: command}
+		return UnknownCommandError{command: command}
 	}
 
 	if err := exe.Parse(args); err != nil {

internal/executor/flags.go

@@ -7,7 +7,6 @@ const (
 	flagInstance     = "instance"
 	flagListID       = "list-id"
 	flagListTitle    = "list-title"
-	flagPollOption   = "poll-option"
 	flagStatusID     = "status-id"
 	flagTag          = "tag"
 	flagTo           = "to"

internal/executor/mute.go

@@ -1,7 +1,6 @@
 package executor
 
 import (
-	"errors"
 	"fmt"
 
 	"codeflow.dananglin.me.uk/apollo/enbas/internal/client"
@@ -69,13 +68,14 @@ func (m *MuteExecutor) muteStatus(gtsClient *client.Client) error {
 		for _, mention := range status.Mentions {
 			if mention.ID == myAccountID {
 				canMute = true
+
 				break
 			}
 		}
 	}
 
 	if !canMute {
-		return errors.New("unable to mute the status because you are not the owner and you are not mentioned in it")
+		return Error{"unable to mute the status because the status does not belong to you nor are you mentioned in it"}
 	}
 
 	if err := gtsClient.MuteStatus(m.statusID); err != nil {

internal/executor/remove.go

@@ -39,8 +39,8 @@ func (r *RemoveExecutor) removeFromList(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[r.resourceType]
 	if !ok {
 		return UnsupportedRemoveOperationError{
-			ResourceType:           r.resourceType,
-			RemoveFromResourceType: r.fromResourceType,
+			resourceType:           r.resourceType,
+			removeFromResourceType: r.fromResourceType,
 		}
 	}
 
@@ -84,8 +84,8 @@ func (r *RemoveExecutor) removeFromAccount(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[r.resourceType]
 	if !ok {
 		return UnsupportedRemoveOperationError{
-			ResourceType:           r.resourceType,
-			RemoveFromResourceType: r.fromResourceType,
+			resourceType:           r.resourceType,
+			removeFromResourceType: r.fromResourceType,
 		}
 	}
 
@@ -115,8 +115,8 @@ func (r *RemoveExecutor) removeFromBookmarks(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[r.resourceType]
 	if !ok {
 		return UnsupportedRemoveOperationError{
-			ResourceType:           r.resourceType,
-			RemoveFromResourceType: r.fromResourceType,
+			resourceType:           r.resourceType,
+			removeFromResourceType: r.fromResourceType,
 		}
 	}
 
@@ -151,8 +151,8 @@ func (r *RemoveExecutor) removeFromStatus(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[r.resourceType]
 	if !ok {
 		return UnsupportedRemoveOperationError{
-			ResourceType:           r.resourceType,
-			RemoveFromResourceType: r.fromResourceType,
+			resourceType:           r.resourceType,
+			removeFromResourceType: r.fromResourceType,
 		}
 	}
 

internal/executor/show.go

@@ -257,8 +257,8 @@ func (s *ShowExecutor) showFollowers(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[s.fromResourceType]
 	if !ok {
 		return UnsupportedShowOperationError{
-			ResourceType:         s.resourceType,
-			ShowFromResourceType: s.fromResourceType,
+			resourceType:         s.resourceType,
+			showFromResourceType: s.fromResourceType,
 		}
 	}
 
@@ -297,8 +297,8 @@ func (s *ShowExecutor) showFollowing(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[s.fromResourceType]
 	if !ok {
 		return UnsupportedShowOperationError{
-			ResourceType:         s.resourceType,
-			ShowFromResourceType: s.fromResourceType,
+			resourceType:         s.resourceType,
+			showFromResourceType: s.fromResourceType,
 		}
 	}
 
@@ -444,8 +444,8 @@ func (s *ShowExecutor) showMedia(gtsClient *client.Client) error {
 	doFunc, ok := funcMap[s.fromResourceType]
 	if !ok {
 		return UnsupportedShowOperationError{
-			ResourceType:         s.resourceType,
-			ShowFromResourceType: s.fromResourceType,
+			resourceType:         s.resourceType,
+			showFromResourceType: s.fromResourceType,
 		}
 	}
 

internal/executor/unmute.go

@@ -1,7 +1,6 @@
 package executor
 
 import (
-	"errors"
 	"fmt"
 
 	"codeflow.dananglin.me.uk/apollo/enbas/internal/client"
@@ -64,13 +63,14 @@ func (m *UnmuteExecutor) unmuteStatus(gtsClient *client.Client) error {
 		for _, mention := range status.Mentions {
 			if mention.ID == myAccountID {
 				canUnmute = true
+
 				break
 			}
 		}
 	}
 
 	if !canUnmute {
-		return errors.New("unable to unmute the status because you are not the owner and you are not mentioned in it")
+		return Error{"unable to unmute the status because the status does not belong to you nor are you mentioned in it"}
 	}
 
 	if err := gtsClient.UnmuteStatus(m.statusID); err != nil {

internal/printer/printer.go

@@ -143,11 +143,11 @@ func (p Printer) fullDisplayNameFormat(displayName, acct string) string {
 }
 
 func (p Printer) formatDate(date time.Time) string {
-	return date.Local().Format(dateFormat)
+	return date.Local().Format(dateFormat) //nolint:gosmopolitan
 }
 
 func (p Printer) formatDateTime(date time.Time) string {
-	return date.Local().Format(dateTimeFormat)
+	return date.Local().Format(dateTimeFormat) //nolint:gosmopolitan
 }
 
 func (p Printer) print(text string) {

internal/utilities/utilities.go

@@ -50,7 +50,7 @@ func OpenLink(browser, url string) error {
 	cmd := strings.Split(browser, " ")
 	cmd = append(cmd, url)
 
-	command := exec.Command(cmd[0], cmd[1:]...)
+	command := exec.Command(cmd[0], cmd[1:]...) //nolint:gosec
 
 	if err := command.Start(); err != nil {
 		return fmt.Errorf("received an error after starting the program to view the link: %w", err)