fix: use git show instead of git log (#118)

git log showed all commits to the given commit and hence was running out of memory

src/adapter.ts

@@ -30,9 +30,9 @@ export interface TableRow {
     id: number
     name: string
     type: TaskType
-    commit: string
+    commit: string | null
     head: string
-    applied_at: Date
+    applied_at: Date | null
 }
 
 export abstract class DbAdapter {
@@ -85,9 +85,9 @@ export abstract class DbAdapter {
             id: row.id,
             type: row.type,
             migration: new Migration(row.name),
-            commit: new Commit({ sha1: row.commit }),
+            commit: row.commit ? new Commit({ sha1: row.commit }) : undefined,
             head: new Commit({ sha1: row.head }),
-            appliedAt: row.applied_at,
+            appliedAt: row.applied_at || undefined,
         })
         return task
     }

src/adapters/postgres.ts

@@ -34,7 +34,7 @@ export class PostgresAdapter extends DbAdapter {
             CREATE TABLE IF NOT EXISTS "merkel_meta" (
                 "id" SERIAL NOT NULL PRIMARY KEY,
                 "name" TEXT NOT NULL,
-                "type" merkel_migration_type,
+                "type" merkel_migration_type NOT NULL,
                 "commit" TEXT,
                 "head" TEXT NOT NULL,
                 "applied_at" TIMESTAMP WITH TIME ZONE

src/git.ts

@@ -54,7 +54,7 @@ export class Commit {
      */
     public async loadSubject(): Promise<void> {
         if (this.message === undefined) {
-            const [stdout] = await execFile('git', ['log', '--format=%B', this.sha1])
+            const [stdout] = await execFile('git', ['show', '--format=%B', this.sha1])
             this.message = stdout.toString()
         }
     }