fix(template): dynamically set default schema alias in typescript type generation

[bug-author]

What kind of change does this PR introduce?

This PR fixes the incorrect default alias generation for TypeScript type schemas when using a single non‑public schema with supabase gen types.

What is the current behavior?

Currently, the TypeScript template always hardcodes the default schema alias as:

export type PublicSchema = Database[Extract<keyof Database, "public">]

This means that when a user generates types using a non‑public schema (for example, --schema robo), the generated helper types (for example. Tables<"test_table">) incorrectly reference the public schema, even if no tables exist there.

Relevant issues:

• cli: #3146, #3061
• postgres-meta: Improve generated TS schemas with supabase gen types #833 (for additional context)

What is the new behavior?

This PR updates the TypeScript template in pg‑meta so that when exactly one non‑public schema is provided, the template automatically uses the environment variable PG_META_GENERATE_TYPES_DEFAULT_SCHEMA to generate a default alias. For example, if the schema provided is "robo", the template will now output:

export type DefaultSchema = Database[Extract<keyof Database, "robo">]
export type DefaultSchemaOrPublic = DefaultSchema

The helper types (Tables, TablesInsert, etc.) reference DefaultSchemaOrPublic instead of the hardcoded "public". In multi‑schema scenarios, the environment variable is not set, and the default behavior (using "public") remains, the users can explicitly specify the schema for non-public tables.

This change ensures:

• In single‑schema mode with a non‑public schema, shorthand type references (like Tables<"test_table">) correctly resolve to Database["robo"]["Tables"]["test_table"].
• In multi‑schema mode, users must explicitly specify which schema to use (for example, Tables<{ schema: "robo" }, "test_table">).

Additional context

Usage example

CREATE SCHEMA robo;
CREATE TABLE robo.test_table (
  id SERIAL PRIMARY KEY,
  name TEXT
);


CREATE TABLE public.example_table (
  id SERIAL PRIMARY KEY,
  description TEXT
);

// Scenario 1: No schema flag (defaults to "public")
import * as PublicTypes from "./dbTypes-public";

type PublicExampleRow = PublicTypes.Tables<"example_table">;

// Scenario 2: Single non‑public schema (e.g. "robo")
import * as RoboTypes from "./dbTypesRobo";

type RoboExampleRow = RoboTypes.Tables<"test_table">;

// Scenario 3: Multiple schemas specified (e.g. "public" and "robo")
import * as MultiTypes from "./dbTypes-multi";

type MultiPublicRow = MultiTypes.Tables<"example_table">;
type MultiRoboRow = MultiTypes.Tables<{ schema: "robo" }, "test_table">;

// examples
const publicRow: PublicExampleRow = {
  id: 1,
  description: "A public record",
};


const roboRow: RoboExampleRow = {
  id: 10,
  name: "Robo record",
};

const multiPublicRow: MultiPublicRow = {
  id: 2,
  description: "Multi public record",
};

const multiRoboRow: MultiRoboRow = {
  id: 20,
  name: null,
};

Corresponding cli PR

[soedirgo]

Thanks @bug-author! Left some comments

[bug-author]

@soedirgo Thank you for the review. I have made the suggested changes:

• Moved the default schema constant to src/server/constants.ts
• Refactored schema aliases to use DefaultSchema only

Thanks for helping me refine the implementation.

[coveralls]

Pull Request Test Coverage Report for Build 13716318077

Details

• 4 of 4 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 75.334%

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Totals
Change from base Build 13671731927:	0.01%
Covered Lines:	4912
Relevant Lines:	6434

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💛 - Coveralls

[soedirgo]

Thanks again @bug-author!

[bug-author]

Hi @soedirgo

I appreciate you taking the time to refine the code, I’ll make sure to pay even closer attention to code quality in future contributions. 🫡

Thanks again!