refactor: define all errors as variables (#837)

Author: morremeyer

pkg/controllers/month_config_test.go

@@ -162,7 +162,7 @@ func (suite *TestSuiteStandard) TestMonthConfigsOptions() {
 		errMsg   string
 	}{
 		{"Bad Envelope ID", "Definitely-Not-A-UUID", "1984-03", http.StatusBadRequest, "not a valid UUID"},
-		{"Invalid Month", envelope.Data.ID.String(), "2000-00", http.StatusBadRequest, "Could not parse the specified month"},
+		{"Invalid Month", envelope.Data.ID.String(), "2000-00", http.StatusBadRequest, "could not parse the specified month"},
 		{"No envelope", uuid.New().String(), "1984-03", http.StatusNoContent, ""},
 		{"No MonthConfig", envelope.Data.ID.String(), "1984-03", http.StatusNoContent, ""},
 		{"Existing", envelope.Data.ID.String(), "2014-05", http.StatusNoContent, ""},

pkg/httperrors/errors.go

@@ -18,11 +18,19 @@ import (
 )
 
 var (
-	ErrInvalidQueryString = errors.New("the query string contains unparseable data. Please check the values")
-	ErrInvalidUUID        = errors.New("the specified resource ID is not a valid UUID")
-	ErrNoResource         = errors.New("there is no resource for the ID you specified")
-	ErrDatabaseClosed     = errors.New("there is a problem with the database connection, please try again later")
-	ErrRequestBodyEmpty   = errors.New("the request body must not be empty")
+	ErrInvalidQueryString            = errors.New("the query string contains unparseable data. Please check the values")
+	ErrInvalidUUID                   = errors.New("the specified resource ID is not a valid UUID")
+	ErrNoResource                    = errors.New("there is no resource for the ID you specified")
+	ErrDatabaseClosed                = errors.New("there is a problem with the database connection, please try again later")
+	ErrDatabaseReadOnly              = errors.New("the database is currently in read-only mode, please try again later")
+	ErrRequestBodyEmpty              = errors.New("the request body must not be empty")
+	ErrInvalidMonth                  = errors.New("could not parse the specified month, did you use YYYY-MM format?")
+	ErrAccountNameNotUnique          = errors.New("the account name must be unique for the budget")
+	ErrCategoryNameNotUnique         = errors.New("the category name must be unique for the budget")
+	ErrEnvelopeNameNotUniqe          = errors.New("the envelope name must be unique for the category")
+	ErrMultipleAllocations           = errors.New("you can not create multiple allocations for the same month")
+	ErrSourceEqualsDestination       = errors.New("source and destination accounts for a transaction must be different")
+	ErrReferenceResourceDoesNotExist = errors.New("a resource you are referencing in another resource does not exist")
 )
 
 // Generate a struct containing the HTTP error on the fly.
@@ -61,7 +69,7 @@ func InvalidQueryString(c *gin.Context) {
 }
 
 func InvalidMonth(c *gin.Context) {
-	New(c, http.StatusBadRequest, "Could not parse the specified month, did you use YYYY-MM format?")
+	New(c, http.StatusBadRequest, ErrInvalidMonth.Error())
 }
 
 // GenericDBError wraps DBError with a more specific error message for not found errors.
@@ -91,38 +99,38 @@ func DBError(c *gin.Context, err error) Error {
 
 	// Account name must be unique per Budget
 	if strings.Contains(err.Error(), "UNIQUE constraint failed: accounts.name, accounts.budget_id") {
-		return Error{Status: http.StatusBadRequest, Err: errors.New("the account name must be unique for the budget")}
+		return Error{Status: http.StatusBadRequest, Err: ErrAccountNameNotUnique}
 	}
 
 	// Category names need to be unique per budget
 	if strings.Contains(err.Error(), "UNIQUE constraint failed: categories.name, categories.budget_id") {
-		return Error{Status: http.StatusBadRequest, Err: errors.New("the category name must be unique for the budget")}
+		return Error{Status: http.StatusBadRequest, Err: ErrCategoryNameNotUnique}
 	}
 
 	// Unique envelope names per category
 	if strings.Contains(err.Error(), "UNIQUE constraint failed: envelopes.name, envelopes.category_id") {
-		return Error{Status: http.StatusBadRequest, Err: errors.New("the envelope name must be unique for the category")}
+		return Error{Status: http.StatusBadRequest, Err: ErrEnvelopeNameNotUniqe}
 	}
 
 	// Only one allocation per envelope per month
 	if strings.Contains(err.Error(), "UNIQUE constraint failed: allocations.month, allocations.envelope_id") {
-		return Error{Status: http.StatusBadRequest, Err: errors.New("you can not create multiple allocations for the same month")}
+		return Error{Status: http.StatusBadRequest, Err: ErrMultipleAllocations}
 	}
 
 	// Source and destination accounts need to be different
 	if strings.Contains(err.Error(), "CHECK constraint failed: source_destination_different") {
-		return Error{Status: http.StatusBadRequest, Err: errors.New("source and destination accounts for a transaction must be different")}
+		return Error{Status: http.StatusBadRequest, Err: ErrSourceEqualsDestination}
 	}
 
 	// General message when a field references a non-existing resource
 	if strings.Contains(err.Error(), "constraint failed: FOREIGN KEY constraint failed") {
-		return Error{Status: http.StatusBadRequest, Err: errors.New("there is no resource for the ID you specificed in the reference to another resource")}
+		return Error{Status: http.StatusBadRequest, Err: ErrReferenceResourceDoesNotExist}
 	}
 
 	// Database is read only or file has been deleted
 	if strings.Contains(err.Error(), "attempt to write a readonly database (1032)") {
-		log.Error().Msgf("Database is in read-only mode. This might be due to the file being deleted: %#v", err)
-		return Error{Status: http.StatusInternalServerError, Err: errors.New("the database is currently in read-only mode, please try again later")}
+		log.Error().Msgf("Database is in read-only mode. This might be due to the file having been deleted: %#v", err)
+		return Error{Status: http.StatusInternalServerError, Err: ErrDatabaseReadOnly}
 	}
 
 	// A general error we do not know more about

pkg/httperrors/errors_test.go

@@ -166,7 +166,7 @@ func TestDatabaseErrorMessages(t *testing.T) {
 		{http.StatusBadRequest, "UNIQUE constraint failed: categories.name, categories.budget_id", "the category name must be unique for the budget"},
 		{http.StatusBadRequest, "UNIQUE constraint failed: envelopes.name, envelopes.category_id", "the envelope name must be unique for the category"},
 		{http.StatusBadRequest, "UNIQUE constraint failed: allocations.month, allocations.envelope_id", "you can not create multiple allocations for the same month"},
-		{http.StatusBadRequest, "constraint failed: FOREIGN KEY constraint failed", "there is no resource for the ID you specificed in the reference to another resource"},
+		{http.StatusBadRequest, "constraint failed: FOREIGN KEY constraint failed", "a resource you are referencing in another resource does not exist"},
 		{http.StatusInternalServerError, "This is a very weird error", "an error occurred on the server during your request, please contact your server administrator. The request id is '', send this to your server administrator to help them finding the problem"},
 		{http.StatusInternalServerError, "attempt to write a readonly database (1032)", "the database is currently in read-only mode, please try again later"},
 	}
@@ -221,7 +221,7 @@ func TestDatabaseNo(t *testing.T) {
 		{http.StatusBadRequest, "UNIQUE constraint failed: categories.name, categories.budget_id", "the category name must be unique for the budget"},
 		{http.StatusBadRequest, "UNIQUE constraint failed: envelopes.name, envelopes.category_id", "the envelope name must be unique for the category"},
 		{http.StatusBadRequest, "UNIQUE constraint failed: allocations.month, allocations.envelope_id", "you can not create multiple allocations for the same month"},
-		{http.StatusBadRequest, "constraint failed: FOREIGN KEY constraint failed", "there is no resource for the ID you specificed in the reference to another resource"},
+		{http.StatusBadRequest, "constraint failed: FOREIGN KEY constraint failed", "a resource you are referencing in another resource does not exist"},
 		{http.StatusInternalServerError, "This is a very weird error", "an error occurred on the server during your request, please contact your server administrator. The request id is '', send this to your server administrator to help them finding the problem"},
 		{http.StatusInternalServerError, "attempt to write a readonly database (1032)", "the database is currently in read-only mode, please try again later"},
 	}