refactor: Remove DumpSchema

This feature adds too much complexity to the drivers.

Existing commands such as pg_dump and mysqldump do a better job of
capturing the myriad of input flags. So, removing all of this feels
pretty liberating right now.

Fun fact: All the mysql driver tests pass now.

README.md

@@ -98,8 +98,6 @@ godfish rollback
 # rollback and re-apply the last migration
 godfish remigrate
 
-godfish dump-schema > db/schema.sql
-
 # show build metadata
 godfish version
 godfish version -json

driver.go

@@ -29,8 +29,6 @@ type Driver interface {
  // versions once they've been applied. The version should be a timestamp as
  // a string, formatted as the TimeFormat variable in this package.
  CreateSchemaMigrationsTable() error
- // DumpSchema should output the database structure to stdout.
- DumpSchema() error
  // Execute runs the schema change and commits it to the database. The query
  // parameter is a SQL string and may contain placeholders for the values in
  // args. Input should be passed to conn so it could be sanitized, escaped.

drivers/mysql/mysql.go

@@ -4,7 +4,6 @@ import (
  "database/sql"
  "fmt"
  "os"
- "os/exec"
  "regexp"
  "strings"
 
@@ -115,27 +114,6 @@ func (d *driver) CreateSchemaMigrationsTable() (err error) {
  return
 }
 
-func (d *driver) DumpSchema() (err error) {
- params := d.dsn
- cmd := exec.Command(
- "mysqldump",
- "--user", params.User, "--password="+params.Pass, // skip password prompt by a omitting space
- "--host", params.Host, "--port", params.Port,
- "--comments", "--no-data", "--routines", "--triggers", "--tz-utc",
- "--skip-add-drop-table", "--add-locks", "--create-options", "--set-charset",
- params.Name,
- )
-
- out, err := cmd.Output()
- if val, ok := err.(*exec.ExitError); ok {
- fmt.Println(string(val.Stderr))
- err = val
- return
- }
- fmt.Println(string(out))
- return
-}
-
 func (d *driver) AppliedVersions() (out godfish.AppliedVersions, err error) {
  rows, err := d.connection.Query(
  `SELECT migration_id FROM schema_migrations ORDER BY migration_id ASC`,

drivers/postgres/postgres.go

@@ -1,11 +1,8 @@
 package postgres
 
 import (
- "bytes"
  "database/sql"
- "fmt"
  "os"
- "os/exec"
 
  "github.com/lib/pq"
  "github.com/rafaelespinoza/godfish"
@@ -90,21 +87,6 @@ func (d *driver) CreateSchemaMigrationsTable() (err error) {
  return
 }
 
-func (d *driver) DumpSchema() (err error) {
- var out bytes.Buffer
- cmd := exec.Command(
- "pg_dump",
- "--schema-only", "--no-acl", "--no-owner", "--no-password",
- d.dsn.Name,
- )
- cmd.Stdout = &out
- if err = cmd.Run(); err != nil {
- return
- }
- fmt.Println(out.String())
- return
-}
-
 func (d *driver) AppliedVersions() (out godfish.AppliedVersions, err error) {
  rows, err := d.connection.Query(
  `SELECT migration_id FROM schema_migrations ORDER BY migration_id ASC`,

godfish.go

@@ -190,15 +190,6 @@ func CreateSchemaMigrationsTable(driver Driver) (err error) {
  return driver.CreateSchemaMigrationsTable()
 }
 
-// DumpSchema describes the database structure and outputs to standard out.
-func DumpSchema(driver Driver) (err error) {
- if _, err = driver.Connect(); err != nil {
- return err
- }
- defer driver.Close()
- return driver.DumpSchema()
-}
-
 // Info displays the outputs of various helper functions.
 func Info(driver Driver, directoryPath string, direction Direction, finishAtVersion string) (err error) {
  if _, err = driver.Connect(); err != nil {

internal/commands/commands.go

@@ -200,28 +200,6 @@ var subcommands = map[string]*subcommand{
  return migration.GenerateFiles()
  },
  },
- "dump-schema": &subcommand{
- description: "generate a sql file describing the db schema",
- setup: func(a *arguments) *flag.FlagSet {
- flags := flag.NewFlagSet("dump-schema", flag.ExitOnError)
- flags.Usage = func() {
- fmt.Printf(`Usage: %s dump-schema
-
- Print a database structure file to standard output.`,
- bin)
- printFlagDefaults(flags)
- }
- return flags
- },
- run: func(a arguments) error {
- driver, err := bootDriver(a.DSN)
- if err != nil {
- return err
- }
- godfish.DumpSchema(driver)
- return nil
- },
- },
  "info": &subcommand{
  description: "output current state of migrations",
  setup: func(a *arguments) *flag.FlagSet {

internal/stub/driver.go

@@ -29,7 +29,6 @@ func (d *Driver) CreateSchemaMigrationsTable() error {
  }
  return d.err
 }
-func (d *Driver) DumpSchema() error { return d.err }
 func (d *Driver) Execute(q string, a ...interface{}) error {
  if strings.Contains(q, "invalid SQL") {
  return fmt.Errorf(q)

internal/test.go

@@ -133,23 +133,6 @@ func RunDriverTests(t *testing.T, dsn godfish.DSN) {
  })
  })
 
- t.Run("DumpSchema", func(t *testing.T) {
- path, err := setup(driver, t.Name(), _DefaultTestDriverStubs, "34560102030405")
- if err != nil {
- t.Errorf("could not setup test; %v", err)
- return
- }
- defer teardown(driver, path, "foos", "bars")
-
- err = godfish.DumpSchema(driver)
- if err != nil {
- t.Errorf(
- "test %q %q; could not dump schema; %v",
- driver.Name(), t.Name(), err,
- )
- }
- })
-
  t.Run("ApplyMigration", func(t *testing.T) {
  // testSetupState describes the state of the database before calling
  // ApplyMigration.