Tern (#286)

* add support for tern migration tool (#284)

Co-authored-by: Kyle Conroy <kyle@conroy.org>

* dinosql/migrate: Fix tern tests

Co-authored-by: Ural Davletshin <ural.davletshin@gmail.com>

Author: kyleconroy

docs/migrations.md

@@ -4,6 +4,7 @@ sqlc will ignore rollback statements when parsing migration SQL files. The follo
 
 - [goose](https://github.com/pressly/goose)
 - [sql-migrate](https://github.com/rubenv/sql-migrate)
+- [tern](https://github.com/jackc/tern)
 
 ## goose
 
@@ -50,3 +51,20 @@ type People struct {
 	ID    int32
 }
 ```
+
+### tern
+
+```sql
+CREATE TABLE comment (id int NOT NULL, text text NOT NULL);
+---- create above / drop below ----
+DROP TABLE comment;
+```
+
+```go
+package db
+
+type Comment struct {
+	ID     int32 
+	Text   string 
+}
+```

internal/dinosql/migrations.go

@@ -9,6 +9,7 @@ import (
 //
 // goose:       -- +goose Down
 // sql-migrate: -- +migrate Down
+// tern: ---- create above / drop below ----
 func RemoveRollbackStatements(contents string) string {
 	s := bufio.NewScanner(strings.NewReader(contents))
 	var lines []string
@@ -19,6 +20,9 @@ func RemoveRollbackStatements(contents string) string {
 		if strings.HasPrefix(s.Text(), "-- +migrate Down") {
 			break
 		}
+		if strings.HasPrefix(s.Text(), "---- create above / drop below ----") {
+			break
+		}
 		lines = append(lines, s.Text())
 	}
 	return strings.Join(lines, "\n")

internal/dinosql/migrations_test.go

@@ -35,11 +35,25 @@ const outputMigrate = `
 CREATE TABLE people (id int);
 `
 
+const inputTern = `
+-- Write your migrate up statements here
+ALTER TABLE todo RENAME COLUMN done TO is_done;
+---- create above / drop below ----
+ALTER TABLE todo RENAME COLUMN is_done TO done;
+`
+
+const outputTern = `
+-- Write your migrate up statements here
+ALTER TABLE todo RENAME COLUMN done TO is_done;`
+
 func TestRemoveRollback(t *testing.T) {
 	if diff := cmp.Diff(outputGoose, RemoveRollbackStatements(inputGoose)); diff != "" {
 		t.Errorf("goose migration mismatch:\n%s", diff)
 	}
 	if diff := cmp.Diff(outputMigrate, RemoveRollbackStatements(inputMigrate)); diff != "" {
 		t.Errorf("sql-migrate migration mismatch:\n%s", diff)
 	}
+	if diff := cmp.Diff(outputTern, RemoveRollbackStatements(inputTern)); diff != "" {
+		t.Errorf("tern migration mismatch:\n%s", diff)
+	}
 }