Initial implementation

Makefile

@@ -0,0 +1,5 @@
+check:
+	go fmt ./...
+
+test:
+	go test -race -count 1 ./...

foundation.go

@@ -0,0 +1,177 @@
+package main
+
+import (
+	"database/sql"
+	"io/ioutil"
+	"testing"
+
+	"github.com/jmoiron/sqlx"
+)
+
+type Foundation struct {
+	t            *testing.T
+	currentStep  int
+	stepByStep   bool
+	migrator     Migrator
+	db           *sqlx.DB
+	interceptors map[int]Interceptor
+}
+
+type Migrator interface {
+	DB() *sql.DB
+	DriverName() string
+	Setup() error
+	MigrateToStep(step int) error
+	TearDown() error
+}
+
+type Interceptor func() error
+
+// ToDo: change T to TB?
+func New(t *testing.T, migrator Migrator) *Foundation {
+	if err := migrator.Setup(); err != nil {
+		t.Fatalf("error setting up the migrator: %s", err)
+	}
+
+	db := sqlx.NewDb(migrator.DB(), migrator.DriverName())
+
+	return &Foundation{
+		t:           t,
+		currentStep: 0,
+		// if true, will run the migrator Step function once per step
+		// instead of just once with the final step
+		stepByStep: false,
+		migrator:   migrator,
+		db:         db,
+	}
+}
+
+func (f *Foundation) RegisterInterceptors(interceptors map[int]Interceptor) *Foundation {
+	f.interceptors = interceptors
+	return f
+}
+
+func (f *Foundation) SetStepByStep(stepByStep bool) *Foundation {
+	f.stepByStep = stepByStep
+	return f
+}
+
+// calculateNextStep returns the next step in the chain that has an
+// interceptor or the final step to migrate to
+func (f *Foundation) calculateNextStep(step int) int {
+	// should never happen
+	if f.currentStep >= step {
+		// nothing to do
+		return step // ToDo: or 0? merge the two conditions
+	}
+
+	// if there are no interceptors, next step is directly the final
+	// one
+	if f.interceptors == nil {
+		return step
+	}
+
+	i := f.currentStep
+	for {
+		i++
+
+		if _, ok := f.interceptors[i]; ok {
+			break
+		}
+
+		if step == i {
+			break
+		}
+	}
+
+	return i
+}
+
+func (f *Foundation) MigrateToStep(step int) *Foundation {
+	if step == f.currentStep {
+		// log nothing to do
+		return f
+	}
+
+	if step < f.currentStep {
+		f.t.Fatal("Down migrations not supported yet")
+	}
+
+	// if there are no interceptors, just migrate to the last step
+	if f.interceptors == nil {
+		if err := f.migrateToStep(step); err != nil {
+			f.t.Fatalf("migration to step %d failed: %s", step, err)
+		}
+
+		return f
+	}
+
+	for f.currentStep < step {
+		nextStep := f.calculateNextStep(step)
+
+		if err := f.migrateToStep(nextStep); err != nil {
+			f.t.Fatalf("migration to step %d failed: %s", nextStep, err)
+		}
+
+		interceptorFn, ok := f.interceptors[nextStep]
+		if ok {
+			if err := interceptorFn(); err != nil {
+				f.t.Fatalf("interceptor function for step %d failed", nextStep)
+			}
+		}
+	}
+
+	return f
+}
+
+// migrateToStep executes the migrator function to migrate to a
+// specific step and updates the foundation currentStep to reflect the
+// result. This function doesn't take into account interceptors, that
+// happens on MigrateToStep
+func (f *Foundation) migrateToStep(step int) error {
+	if f.stepByStep {
+		for f.currentStep < step {
+			if err := f.migrator.MigrateToStep(f.currentStep + 1); err != nil {
+				return err
+			}
+
+			f.currentStep++
+		}
+
+		return nil
+	}
+
+	if err := f.migrator.MigrateToStep(step); err != nil {
+		return err
+	}
+
+	f.currentStep = step
+	return nil
+}
+
+func (f *Foundation) TearDown() {
+	if err := f.migrator.TearDown(); err != nil {
+		f.t.Fatalf("error tearing down migrator: %s", err)
+	}
+}
+
+func (f *Foundation) DB() *sqlx.DB {
+	return f.db
+}
+
+func (f *Foundation) Exec(s string) *Foundation {
+	if _, err := f.DB().Exec(s); err != nil {
+		f.t.Fatalf("failed to run %s: %s", s, err)
+	}
+
+	return f
+}
+
+func (f *Foundation) ExecFile(filePath string) *Foundation {
+	b, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		f.t.Fatalf("failed to read file %s: %s", filePath, err)
+	}
+
+	return f.Exec(string(b))
+}

foundation_test.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestCalculateNextStep(t *testing.T) {
+	t.Run("should return the last step if no interceptors are set", func(t *testing.T) {
+		f := New(t, &SampleMigrator{})
+
+		require.Equal(t, 7, f.calculateNextStep(7))
+		f.currentStep = 5
+		require.Equal(t, 7, f.calculateNextStep(7))
+	})
+
+	t.Run("should return the next step with an interceptor", func(t *testing.T) {
+		interceptors := map[int]Interceptor{
+			3:  func() error { return nil },
+			12: func() error { return nil },
+		}
+
+		f := New(t, &SampleMigrator{}).
+			RegisterInterceptors(interceptors)
+
+		require.Equal(t, 3, f.calculateNextStep(7))
+		f.currentStep = 5
+		require.Equal(t, 7, f.calculateNextStep(7))
+		require.Equal(t, 12, f.calculateNextStep(15))
+		f.currentStep = 12
+		require.Equal(t, 15, f.calculateNextStep(15))
+	})
+}

go.mod

@@ -1,3 +1,14 @@
 module git.ctrlz.es/mgdelacroix/foundation
 
 go 1.18
+
+require (
+	github.com/jmoiron/sqlx v1.3.5
+	github.com/stretchr/testify v1.8.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,23 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-sql-driver/mysql v1.6.0 h1:BCTh4TKNUYmOmMUcQ3IipzF5prigylS7XXjEkfCHuOE=
+github.com/go-sql-driver/mysql v1.6.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
+github.com/jmoiron/sqlx v1.3.5 h1:vFFPA71p1o5gAeqtEAwLU4dnX2napprKtHr7PYIcN3g=
+github.com/jmoiron/sqlx v1.3.5/go.mod h1:nRVWtLre0KfCLJvgxzCsLVMogSvQ1zNJtpYr2Ccp0mQ=
+github.com/lib/pq v1.2.0 h1:LXpIM/LZ5xGFhOpXAQUIMM1HdyqzVYM13zNdjCEEcA0=
+github.com/lib/pq v1.2.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
+github.com/mattn/go-sqlite3 v1.14.6 h1:dNPt6NO46WmLVt2DLNpwczCmdV5boIZ6g/tlDrlRUbg=
+github.com/mattn/go-sqlite3 v1.14.6/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0 h1:pSgiaMZlXftHpm5L7V1+rVB+AZJydKsMxsQBIJw4PKk=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

helpers_test.go

@@ -0,0 +1,27 @@
+package main
+
+import "database/sql"
+
+type SampleMigrator struct{}
+
+func (sm *SampleMigrator) DB() *sql.DB {
+	return nil
+}
+
+func (sm *SampleMigrator) DriverName() string {
+	return ""
+}
+
+func (sm *SampleMigrator) Setup() error {
+	return nil
+}
+
+func (sm *SampleMigrator) MigrateToStep(step int) error {
+	return nil
+}
+
+func (sm *SampleMigrator) TearDown() error {
+	return nil
+}
+
+var _ Migrator = &SampleMigrator{}