feat!: more lints and error fixes

This introduces one error type as well.

.golangci.yml

@@ -4,17 +4,22 @@ output:
 
 linters:
   enable:
-    - errcheck
+    - errname
+    - errorlint
     - gocritic
-    - gofmt
+    - goerr113
+    - gofumpt
+    - goheader
     - goimports
+    - gosec
     - gosimple
     - govet
     - ineffassign
     - revive
     - staticcheck
+    - testpackage
+    - thelper
     - typecheck
-    - unused
 
   disable-all: true
 
@@ -25,5 +30,103 @@ linters-settings:
       - style
       - performance
 
+  gofumpt:
+    extra-rules: true
+
+  goheader:
+    values:
+      const:
+        COMPANY: z0ne
+      regexp:
+        FILE: "[a-zA-Z0-9_]+\\.go"
+    template: |-
+      {{ FILE }} Copyright (c) {{ YEAR }} {{ COMPANY }}.
+      All Rights Reserved.
+      Licensed under the Apache 2.0 License.
+      See LICENSE the project root for license information.
+
+      SPDX-License-Identifier: Apache-2.0
+
+  govet:
+    check-shadowing: true
+    enable-all: true
+
+  revive:
+    rules:
+      - name: add-constant
+        arguments:
+          - maxLitCount: "3"
+            allowStrs: '""'
+            allowInts: "0,1,2"
+            allowFloats: "0.0,0.,1.0,1.,2.0,2."
+      - name: argument-limit
+        arguments: [4]
+      - name: atomic
+      - name: bare-return
+      - name: blank-imports
+      - name: bool-literal-in-expr
+      - name: call-to-gc
+      - name: cognitive-complexity
+        arguments: [10]
+      - name: comment-spacings
+        arguments: []
+      - name: confusing-naming
+      - name: confusing-results
+      - name: constant-logical-expr
+      - name: context-as-argument
+      - name: context-keys-type
+      - name: cyclomatic
+        arguments: [10]
+      - name: datarace
+      - name: deep-exit
+      - name: defer
+      - name: dot-imports
+      - name: duplicated-imports
+      - name: early-return
+      - name: empty-block
+      - name: empty-lines
+      - name: error-naming
+      - name: error-return
+      - name: error-strings
+      - name: errorf
+      - name: exported
+        arguments:
+          - "checkPrivateReceivers"
+          - "sayRepetitiveInsteadOfStutters"
+      - name: flag-parameter
+      - name: function-result-limit
+        arguments: [2]
+      - name: function-length
+        arguments: [50, 0]
+      - name: get-return
+      - name: identical-branches
+      - name: if-return
+      - name: increment-decrement
+      - name: indent-error-flow
+      - name: imports-blacklist
+        arguments:
+          - "crypto/md5"
+          - "crypto/sha1"
+      - name: import-shadowing
+      - name: line-length-limit
+        arguments: [120]
+      - name: max-public-structs
+        arguments: [5]
+      - name: time-equal
+      - name: time-naming
+      - name: var-naming
+      - name: var-declaration
+      - name: unconditional-recursion
+      - name: unexported-naming
+      - name: unexported-return
+      - name: unhandled-error
+      - name: unnecessary-stmt
+      - name: unreachable-code
+      - name: unused-parameter
+      - name: unused-receiver
+      - name: use-any
+      - name: useless-break
+      - name: waitgroup-by-value
+
 issues:
   exclude-use-default: false

error.go

@@ -0,0 +1,13 @@
+// error.go Copyright (c) 2023 z0ne.
+// All Rights Reserved.
+// Licensed under the Apache 2.0 License.
+// See LICENSE the project root for license information.
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package mgx
+
+import "errors"
+
+// ErrTooManyAppliedMigrations is returned when more migrations are applied than defined
+var ErrTooManyAppliedMigrations = errors.New("too many applied migrations")

migration.go

@@ -1,3 +1,10 @@
+// migration.go Copyright (c) 2023 z0ne.
+// All Rights Reserved.
+// Licensed under the Apache 2.0 License.
+// See LICENSE the project root for license information.
+//
+// SPDX-License-Identifier: Apache-2.0
+
 // Package mgx is a simple migration tool for pgx
 package mgx
 
@@ -16,14 +23,16 @@ type Migration interface {
 }
 
 type migrationFuncWrapper struct {
-	name string
 	fn   MigrationFunc
+	name string
 }
 
+// Run the migration
 func (m *migrationFuncWrapper) Run(ctx context.Context, tx Commands) error {
 	return m.fn(ctx, tx)
 }
 
+// String returns the name of the migration
 func (m *migrationFuncWrapper) String() string {
 	return m.name
 }

migrator.go

@@ -1,8 +1,14 @@
+// migrator.go Copyright (c) 2023 z0ne.
+// All Rights Reserved.
+// Licensed under the Apache 2.0 License.
+// See LICENSE the project root for license information.
+//
+// SPDX-License-Identifier: Apache-2.0
+
 package mgx
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"log"
 	"time"
@@ -82,32 +88,39 @@ func (m *Migrator) Migrate(ctx context.Context, db Conn) error {
 	}
 
 	if count > len(m.migrations) {
-		return errors.New("migrator: applied migration number on db cannot be greater than the defined migration list")
+		return ErrTooManyAppliedMigrations
 	}
 
 	m.logger.Log("Running missing migrations...", map[string]any{"missing": len(m.migrations) - count})
 
 	// plan migrations
 	for idx, migration := range m.migrations[count:] {
-		tx, err := db.Begin(ctx)
-		if err != nil {
-			return fmt.Errorf("migrator: error while starting transaction: %v", err)
+		err2 := m.applyMigration(ctx, db, migration, idx+count)
+		if err2 != nil {
+			return err2
 		}
+	}
 
-		insertVersion := fmt.Sprintf("INSERT INTO %s (id, version) VALUES ($1, $2)", m.tableName)
-		if err := migrate(ctx, tx, m.logger, insertVersion, migration, idx+count); err != nil {
-			if err := tx.Rollback(ctx); err != nil {
-				panic(fmt.Errorf("migrator: error while rolling back transaction: %v", err))
-			}
-			return fmt.Errorf("migrator: error while running migrations: %v", err)
-		}
+	return nil
+}
 
-		err = tx.Commit(ctx)
-		if err != nil {
-			return fmt.Errorf("migrator: failed to commit transaction: %v", err)
+func (m *Migrator) applyMigration(ctx context.Context, db Conn, migration Migration, version int) error {
+	tx, err := db.Begin(ctx)
+	if err != nil {
+		return fmt.Errorf("migrator: error while starting transaction: %w", err)
+	}
+
+	if errMigration := m.runMigration(ctx, tx, migration, version); errMigration != nil {
+		if errRollback := tx.Rollback(ctx); errRollback != nil {
+			panic(fmt.Errorf("migrator: error while rolling back transaction: %w", errRollback))
 		}
+		return fmt.Errorf("migrator: error while running migrations: %w", errMigration)
 	}
 
+	err = tx.Commit(ctx)
+	if err != nil {
+		return fmt.Errorf("migrator: failed to commit transaction: %w", err)
+	}
 	return nil
 }
 
@@ -143,8 +156,8 @@ func (m *Migrator) countApplied(ctx context.Context, db Conn, tableName string)
 	return count, nil
 }
 
-func migrate(ctx context.Context, db pgx.Tx, logger Logger, insertVersion string, migration Migration, id int) (err error) {
-	logger.Log("applying migration", map[string]any{
+func (m *Migrator) runMigration(ctx context.Context, db pgx.Tx, migration Migration, id int) (err error) {
+	m.logger.Log("applying migration", map[string]any{
 		"id":   id,
 		"name": migration.String(),
 	})
@@ -154,12 +167,13 @@ func migrate(ctx context.Context, db pgx.Tx, logger Logger, insertVersion string
 		return fmt.Errorf("error executing golang migration %s: %w", migration.String(), err)
 	}
 
+	insertVersion := fmt.Sprintf("INSERT INTO %s (id, version) VALUES ($1, $2)", m.tableName)
 	if _, err = db.Exec(ctx, insertVersion, id, migration.String()); err != nil {
 		return fmt.Errorf("error updating migration versions: %w", err)
 	}
 	duration := time.Since(start)
 
-	logger.Log("applied migration", map[string]any{
+	m.logger.Log("applied migration", map[string]any{
 		"id":   id,
 		"name": migration.String(),
 		"took": duration,

migrator_test.go

@@ -1,10 +1,15 @@
+// migrator_test.go Copyright (c) 2023 z0ne.
+// All Rights Reserved.
+// Licensed under the Apache 2.0 License.
+// See LICENSE the project root for license information.
+//
+// SPDX-License-Identifier: Apache-2.0
+
 package mgx_test
 
 import (
 	"context"
 	_ "embed"
-	"errors"
-	"fmt"
 	"os"
 	"testing"
 
@@ -14,7 +19,10 @@ import (
 
 var migrations = []mgx.Migration{
 	mgx.NewRawMigration("raw migration: single query, create table foo", "CREATE TABLE foo (id INT PRIMARY KEY)"),
-	mgx.NewRawMigration("raw migration: multi query, create table bar, alter table bar", "CREATE TABLE bar (id INT PRIMARY KEY); ALTER TABLE bar ADD COLUMN name VARCHAR(255)"),
+	mgx.NewRawMigration(
+		"raw migration: multi query, create table bar, alter table bar",
+		"CREATE TABLE bar (id INT PRIMARY KEY); ALTER TABLE bar ADD COLUMN name VARCHAR(255)",
+	),
 	mgx.NewMigration("fn migration", func(ctx context.Context, cmd mgx.Commands) error {
 		if _, err := cmd.Exec(ctx, "CREATE TABLE foobar (id INT PRIMARY KEY)"); err != nil {
 			return err
@@ -37,10 +45,12 @@ func (t *TestLogger) Log(_ string, _ map[string]any) {
 }
 
 func connectToDatabase(t *testing.T) *pgx.Conn {
+	t.Helper()
+
 	// create db connection
 	url := os.Getenv("POSTGRES")
 	if url == "" {
-		t.Fatal(errors.New("POSTGRES env variable is not set"))
+		t.Fatal("POSTGRES env variable is not set")
 	}
 
 	db, err := pgx.Connect(context.Background(), url)
@@ -144,7 +154,7 @@ func TestPending(t *testing.T) {
 
 	pending, err := migrator.Pending(context.Background(), db)
 	if err == nil && len(pending) != len(migrations) {
-		err = fmt.Errorf("there should be %d pending migrations, only %d found", len(migrations), len(pending))
+		t.Fatalf("there should be %d pending migrations, only %d found", len(migrations), len(pending))
 	}
 
 	if err != nil {

pgx.go

@@ -1,3 +1,10 @@
+// pgx.go Copyright (c) 2023 z0ne.
+// All Rights Reserved.
+// Licensed under the Apache 2.0 License.
+// See LICENSE the project root for license information.
+//
+// SPDX-License-Identifier: Apache-2.0
+
 package mgx
 
 import (