Add status command

src/cli.ts

@@ -8,6 +8,7 @@ import { EnableMirroringCommand } from "./commands/enable-mirroring.js";
 import { EnableRetiredMirroringCommand } from "./commands/enable-retired-mirroring.js";
 import { FillCommand } from "./commands/fill.js";
 import { PrepCommand } from "./commands/prep.js";
+import { StatusCommand } from "./commands/status.js";
 import { SwapCommand } from "./commands/swap.js";
 import { SynchronizeCommand } from "./commands/synchronize.js";
 import { UnprepCommand } from "./commands/unprep.js";
@@ -30,6 +31,7 @@ export function createCli(): Cli {
   cli.register(EnableRetiredMirroringCommand);
   cli.register(FillCommand);
   cli.register(PrepCommand);
+  cli.register(StatusCommand);
   cli.register(SwapCommand);
   cli.register(SynchronizeCommand);
   cli.register(UnprepCommand);

src/commands/status.test.ts

@@ -0,0 +1,45 @@
+import { describe, expect } from "vitest";
+import { sql } from "slonik";
+
+import { commandTest as test } from "../testing/index.js";
+import { StatusCommand } from "./status.js";
+
+describe("StatusCommand", () => {
+  test.scoped({ commandClass: ({}, use) => use(StatusCommand) });
+
+  test.beforeEach(async ({ transaction }) => {
+    await transaction.query(sql.unsafe`
+      CREATE TABLE posts (
+        id SERIAL PRIMARY KEY,
+        created_at DATE NOT NULL
+      )
+    `);
+  });
+
+  test("outputs status as JSON", async ({ cli, commandContext }) => {
+    const exitCode = await cli.run(
+      ["status", "posts", "--json"],
+      commandContext,
+    );
+
+    expect(exitCode).toBe(0);
+    const status = JSON.parse(commandContext.stdout.read()?.toString() ?? "");
+    expect(status).toEqual({
+      intermediateExists: false,
+      partitionCount: 0,
+      mirrorTriggerExists: false,
+      retiredMirrorTriggerExists: false,
+      originalIsPartitioned: false,
+    });
+  });
+
+  test("outputs human-readable status", async ({ cli, commandContext }) => {
+    const exitCode = await cli.run(["status", "posts"], commandContext);
+
+    expect(exitCode).toBe(0);
+    const output = commandContext.stdout.read()?.toString();
+    expect(output).toContain("Table: posts");
+    expect(output).toContain("Intermediate exists:");
+    expect(output).toContain("Original is partitioned:");
+  });
+});

src/commands/status.ts

@@ -0,0 +1,53 @@
+import { Command, Option } from "clipanion";
+
+import { BaseCommand } from "./base.js";
+import { type Pgslice } from "../pgslice.js";
+
+export class StatusCommand extends BaseCommand {
+  static override paths = [["status"]];
+
+  static override usage = Command.Usage({
+    description: "Show status information about a table's partitioning state",
+    details: `
+      This command displays the current state of a table's partitioning workflow,
+      including:
+      - Whether intermediate table exists
+      - Number of partitions
+      - Whether mirroring triggers are enabled
+      - Whether the original table is partitioned
+    `,
+    examples: [
+      ["Show status for a table", "$0 status posts"],
+      ["Show status with explicit schema", "$0 status myschema.posts"],
+      ["Output as JSON", "$0 status posts --json"],
+    ],
+  });
+
+  table = Option.String({ required: true, name: "table" });
+  json = Option.Boolean("--json", false, {
+    description: "Output status as JSON",
+  });
+
+  override async perform(pgslice: Pgslice): Promise<void> {
+    const status = await pgslice.status({ table: this.table });
+
+    if (this.json) {
+      this.context.stdout.write(JSON.stringify(status, null, 2) + "\n");
+    } else {
+      this.context.stdout.write(`Table: ${this.table}\n`);
+      this.context.stdout.write(
+        `Intermediate exists: ${status.intermediateExists}\n`,
+      );
+      this.context.stdout.write(
+        `Original is partitioned: ${status.originalIsPartitioned}\n`,
+      );
+      this.context.stdout.write(`Partition count: ${status.partitionCount}\n`);
+      this.context.stdout.write(
+        `Mirror trigger exists: ${status.mirrorTriggerExists}\n`,
+      );
+      this.context.stdout.write(
+        `Retired mirror trigger exists: ${status.retiredMirrorTriggerExists}\n`,
+      );
+    }
+  }
+}

src/mirroring.ts

@@ -61,12 +61,18 @@ export class Mirroring {
     return sql.identifier([`${this.#source.name}_${suffix}`]);
   }
 
-  get #triggerName() {
+  static triggerNameFor(table: Table, targetType: MirroringTargetType): string {
     const suffix =
-      this.#targetType === "intermediate"
+      targetType === "intermediate"
         ? "mirror_trigger"
         : "retired_mirror_trigger";
-    return sql.identifier([`${this.#source.name}_${suffix}`]);
+    return `${table.name}_${suffix}`;
+  }
+
+  get #triggerName() {
+    return sql.identifier([
+      Mirroring.triggerNameFor(this.#source, this.#targetType),
+    ]);
   }
 
   #buildWhereClause(columns: string[]) {

src/pgslice.test.ts

@@ -666,6 +666,51 @@ describe("Pgslice.addPartitions", () => {
   });
 });
 
+describe("Pgslice.status", () => {
+  test("returns status for a plain table", async ({ pgslice, transaction }) => {
+    await transaction.query(sql.unsafe`
+      CREATE TABLE posts (
+        id SERIAL PRIMARY KEY,
+        created_at DATE NOT NULL
+      )
+    `);
+
+    const status = await pgslice.status({ table: "posts" });
+    expect(status).toEqual({
+      intermediateExists: false,
+      partitionCount: 0,
+      mirrorTriggerExists: false,
+      retiredMirrorTriggerExists: false,
+      originalIsPartitioned: false,
+    });
+  });
+
+  test("returns status after prep", async ({ pgslice, transaction }) => {
+    await transaction.query(sql.unsafe`
+      CREATE TABLE events (
+        id BIGSERIAL PRIMARY KEY,
+        created_at DATE NOT NULL
+      )
+    `);
+
+    await pgslice.prep(transaction, {
+      table: "events",
+      column: "created_at",
+      period: "month",
+      partition: true,
+    });
+
+    const status = await pgslice.status({ table: "events" });
+    expect(status).toEqual({
+      intermediateExists: true,
+      partitionCount: 0,
+      originalIsPartitioned: false,
+      mirrorTriggerExists: false,
+      retiredMirrorTriggerExists: false,
+    });
+  });
+});
+
 describe("Pgslice.synchronize", () => {
   test("synchronizes data", async ({ pgslice, transaction }) => {
     // Create source table with data

src/pgslice.ts

@@ -16,9 +16,11 @@ import type {
   FillOptions,
   Period,
   PrepOptions,
+  StatusOptions,
   SwapOptions,
   SynchronizeBatchResult,
   SynchronizeOptions,
+  TableStatus,
   UnprepOptions,
   UnswapOptions,
 } from "./types.js";
@@ -565,4 +567,43 @@ export class Pgslice {
       }),
     );
   }
+
+  async status(options: StatusOptions): Promise<TableStatus> {
+    const table = Table.parse(options.table);
+    const intermediate = table.intermediate;
+
+    const intermediateExists = await intermediate.exists(this.pool);
+
+    // Check intermediate for partitions pre-swap, original post-swap
+    let partitionCount = 0;
+    if (intermediateExists) {
+      const partitions = await this.start((conn) =>
+        intermediate.partitions(conn),
+      );
+      partitionCount = partitions.length;
+    } else {
+      const partitions = await this.start((conn) => table.partitions(conn));
+      partitionCount = partitions.length;
+    }
+
+    const mirrorTriggerExists = await table.triggerExists(
+      this.pool,
+      Mirroring.triggerNameFor(table, "intermediate"),
+    );
+
+    const retiredMirrorTriggerExists = await table.triggerExists(
+      this.pool,
+      Mirroring.triggerNameFor(table, "retired"),
+    );
+
+    const originalIsPartitioned = await table.isPartitioned(this.pool);
+
+    return {
+      intermediateExists,
+      partitionCount,
+      mirrorTriggerExists,
+      retiredMirrorTriggerExists,
+      originalIsPartitioned,
+    };
+  }
 }

src/table.test.ts

@@ -4,6 +4,104 @@ import { sql } from "slonik";
 import { pgsliceTest as test } from "./testing/index.js";
 import { Table } from "./table.js";
 
+describe("Table.isPartitioned", () => {
+  test("returns true for partitioned table", async ({ transaction }) => {
+    await transaction.query(sql.unsafe`
+      CREATE TABLE test_table (
+        id BIGSERIAL,
+        created_at DATE NOT NULL,
+        PRIMARY KEY (id, created_at)
+      ) PARTITION BY RANGE (created_at)
+    `);
+
+    const table = Table.parse("test_table");
+    const result = await table.isPartitioned(transaction);
+
+    expect(result).toBe(true);
+  });
+
+  test("returns false for regular table", async ({ transaction }) => {
+    await transaction.query(sql.unsafe`
+      CREATE TABLE test_table (id BIGSERIAL PRIMARY KEY, name TEXT)
+    `);
+
+    const table = Table.parse("test_table");
+    const result = await table.isPartitioned(transaction);
+
+    expect(result).toBe(false);
+  });
+
+  test("returns false for non-existent table", async ({ transaction }) => {
+    const table = Table.parse("nonexistent_table");
+    const result = await table.isPartitioned(transaction);
+
+    expect(result).toBe(false);
+  });
+});
+
+describe("Table.triggerExists", () => {
+  test("returns true when trigger exists", async ({ transaction }) => {
+    await transaction.query(sql.unsafe`
+      CREATE TABLE test_table (id BIGSERIAL PRIMARY KEY, name TEXT)
+    `);
+    await transaction.query(sql.unsafe`
+      CREATE FUNCTION test_trigger_fn() RETURNS TRIGGER AS $$
+      BEGIN RETURN NEW; END;
+      $$ LANGUAGE plpgsql
+    `);
+    await transaction.query(sql.unsafe`
+      CREATE TRIGGER test_trigger
+      AFTER INSERT ON test_table
+      FOR EACH ROW EXECUTE FUNCTION test_trigger_fn()
+    `);
+
+    const table = Table.parse("test_table");
+    const result = await table.triggerExists(transaction, "test_trigger");
+
+    expect(result).toBe(true);
+  });
+
+  test("returns false when trigger does not exist", async ({ transaction }) => {
+    await transaction.query(sql.unsafe`
+      CREATE TABLE test_table (id BIGSERIAL PRIMARY KEY, name TEXT)
+    `);
+
+    const table = Table.parse("test_table");
+    const result = await table.triggerExists(
+      transaction,
+      "nonexistent_trigger",
+    );
+
+    expect(result).toBe(false);
+  });
+
+  test("returns false for trigger on different table", async ({
+    transaction,
+  }) => {
+    await transaction.query(sql.unsafe`
+      CREATE TABLE test_table (id BIGSERIAL PRIMARY KEY, name TEXT)
+    `);
+    await transaction.query(sql.unsafe`
+      CREATE TABLE other_table (id BIGSERIAL PRIMARY KEY, name TEXT)
+    `);
+    await transaction.query(sql.unsafe`
+      CREATE FUNCTION test_trigger_fn() RETURNS TRIGGER AS $$
+      BEGIN RETURN NEW; END;
+      $$ LANGUAGE plpgsql
+    `);
+    await transaction.query(sql.unsafe`
+      CREATE TRIGGER test_trigger
+      AFTER INSERT ON other_table
+      FOR EACH ROW EXECUTE FUNCTION test_trigger_fn()
+    `);
+
+    const table = Table.parse("test_table");
+    const result = await table.triggerExists(transaction, "test_trigger");
+
+    expect(result).toBe(false);
+  });
+});
+
 describe("Table.maxId", () => {
   test("returns max bigint ID from table", async ({ transaction }) => {
     await transaction.query(sql.unsafe`

src/table.ts

@@ -155,6 +155,42 @@ export class Table {
     return result.count > 0;
   }
 
+  /**
+   * Checks if this table is a partitioned table (relkind = 'p').
+   */
+  async isPartitioned(connection: CommonQueryMethods): Promise<boolean> {
+    const result = await connection.one(
+      sql.type(z.object({ count: z.coerce.number() }))`
+        SELECT COUNT(*) FROM pg_class c
+        JOIN pg_namespace n ON c.relnamespace = n.oid
+        WHERE n.nspname = ${this.schema}
+          AND c.relname = ${this.name}
+          AND c.relkind = 'p'
+      `,
+    );
+    return result.count > 0;
+  }
+
+  /**
+   * Checks if a trigger with the given name exists on this table.
+   */
+  async triggerExists(
+    connection: CommonQueryMethods,
+    triggerName: string,
+  ): Promise<boolean> {
+    const result = await connection.one(
+      sql.type(z.object({ count: z.coerce.number() }))`
+        SELECT COUNT(*) FROM pg_trigger t
+        JOIN pg_class c ON t.tgrelid = c.oid
+        JOIN pg_namespace n ON c.relnamespace = n.oid
+        WHERE n.nspname = ${this.schema}
+          AND c.relname = ${this.name}
+          AND t.tgname = ${triggerName}
+      `,
+    );
+    return result.count > 0;
+  }
+
   /**
    * Gets column metadata for this table (excluding generated columns).
    */