feat(deparser): add type-name quoting policy for minimal quoting in type positions

__fixtures__/generated/generated.json

@@ -60,6 +60,15 @@
   "pretty/quoting-5.sql": "CREATE FUNCTION faker.boolean() RETURNS boolean AS $EOFCODE$\nBEGIN\n  RETURN random() < 0.5;\nEND;\n$EOFCODE$ LANGUAGE plpgsql",
   "pretty/quoting-6.sql": "CREATE FUNCTION faker.\"boolean\"() RETURNS boolean AS $EOFCODE$\nBEGIN\n  RETURN random() < 0.5;\nEND;\n$EOFCODE$ LANGUAGE plpgsql",
   "pretty/quoting-7.sql": "CREATE DOMAIN origin AS text CHECK (value = pg_catalog.\"substring\"(value, '^(https?://[^/]*)'))",
+  "pretty/quoting-8.sql": "SELECT '{\"a\":1}'::json",
+  "pretty/quoting-9.sql": "SELECT '{\"b\":2}'::jsonb",
+  "pretty/quoting-10.sql": "SELECT true::boolean",
+  "pretty/quoting-11.sql": "SELECT '1 day'::interval",
+  "pretty/quoting-12.sql": "SELECT 42::int",
+  "pretty/quoting-13.sql": "INSERT INTO test_table (data) VALUES ('{\"c\":3}'::json)",
+  "pretty/quoting-14.sql": "SELECT '{\"d\":4}'::myschema.json",
+  "pretty/quoting-15.sql": "SELECT 100::custom.int",
+  "pretty/quoting-16.sql": "SELECT true::myapp.boolean",
   "pretty/procedures-1.sql": "SELECT handle_insert('TYPE_A')",
   "pretty/procedures-2.sql": "SELECT \"HandleInsert\"('TYPE_A', 'Region-1')",
   "pretty/procedures-3.sql": "SELECT compute_score(42, TRUE)",

__fixtures__/kitchen-sink/pretty/quoting.sql

@@ -45,3 +45,33 @@ $EOFCODE$ LANGUAGE plpgsql;
 -- Note: SUBSTRING(value FROM 'pattern') SQL syntax gets deparsed to pg_catalog."substring"(value, 'pattern')
 -- The SQL syntax form cannot be tested here due to AST round-trip differences (COERCE_SQL_SYNTAX vs COERCE_EXPLICIT_CALL)
 CREATE DOMAIN origin AS text CHECK (value = pg_catalog."substring"(value, '^(https?://[^/]*)'));
+
+-- 8. Type name quoting: json type should NOT be quoted (COL_NAME_KEYWORD in type position)
+-- Type names follow a less strict quoting policy than standalone identifiers
+SELECT '{"a":1}'::json;
+
+-- 9. Type name quoting: jsonb type should NOT be quoted
+SELECT '{"b":2}'::jsonb;
+
+-- 10. Type name quoting: boolean type should NOT be quoted (TYPE_FUNC_NAME_KEYWORD in type position)
+SELECT true::boolean;
+
+-- 11. Type name quoting: interval type should NOT be quoted (TYPE_FUNC_NAME_KEYWORD in type position)
+SELECT '1 day'::interval;
+
+-- 12. Type name quoting: int type should NOT be quoted (COL_NAME_KEYWORD in type position)
+SELECT 42::int;
+
+-- 13. Type cast in INSERT VALUES - json type should NOT be quoted
+INSERT INTO test_table (data) VALUES ('{"c":3}'::json);
+
+-- 14. User-defined schema-qualified type with keyword name - should NOT quote the type name
+-- This tests the bug where non-pg_catalog types use quoteIdentifier() for ALL parts
+-- The type name 'json' is a COL_NAME_KEYWORD and should NOT be quoted in type position
+SELECT '{"d":4}'::myschema.json;
+
+-- 15. User-defined schema-qualified type with keyword name 'int' - should NOT quote
+SELECT 100::custom.int;
+
+-- 16. User-defined schema-qualified type with keyword name 'boolean' - should NOT quote
+SELECT true::myapp.boolean;

packages/deparser/QUOTING-RULES.md

@@ -203,6 +203,99 @@ The only difference is that `quoteIdentifierAfterDot()` does not check for keywo
 | `interval` | `"interval"` | `interval` |
 | `my-col` | `"my-col"` | `"my-col"` |
 
+## Type-Name Quoting Policy
+
+Type names in PostgreSQL have their own quoting policy that is less strict than standalone identifiers but different from after-dot identifiers.
+
+### The Problem
+
+When you have a user-defined schema-qualified type like `myschema.json`, the type name `json` is a `COL_NAME_KEYWORD`. Using strict quoting (`quoteIdentifier()`) would produce `myschema."json"`, which is unnecessarily verbose.
+
+However, we cannot use the fully relaxed after-dot policy (`quoteIdentifierAfterDot()`) because type names are not in the same permissive grammar slot as identifiers after a dot in qualified names.
+
+### The Type-Name Quoting Algorithm
+
+The `QuoteUtils.quoteIdentifierTypeName()` function implements a middle-ground policy:
+
+- **Quote for lexical reasons**: uppercase, special characters, leading digits, embedded quotes
+- **Quote only RESERVED_KEYWORD**: keywords like `select`, `from`, `where` must be quoted
+- **Allow COL_NAME_KEYWORD unquoted**: keywords like `json`, `int`, `boolean` are allowed
+- **Allow TYPE_FUNC_NAME_KEYWORD unquoted**: keywords like `interval`, `left`, `right` are allowed
+
+```
+function quoteIdentifierTypeName(ident):
+    if ident is empty:
+        return ident
+
+    safe = true
+
+    // Rule 1: First character must be lowercase letter or underscore
+    if first_char not in [a-z_]:
+        safe = false
+
+    // Rule 2: All characters must be in safe set
+    for each char in ident:
+        if char not in [a-z0-9_]:
+            safe = false
+
+    // Rule 3: Only quote RESERVED_KEYWORD (not COL_NAME_KEYWORD or TYPE_FUNC_NAME_KEYWORD)
+    if safe:
+        kwKind = keywordKindOf(ident)
+        if kwKind == RESERVED_KEYWORD:
+            safe = false
+
+    if safe:
+        return ident  // No quoting needed
+
+    // Build quoted identifier with escaped embedded quotes
+    result = '"'
+    for each char in ident:
+        if char == '"':
+            result += '"'
+        result += char
+    result += '"'
+
+    return result
+```
+
+### Comparison of Quoting Policies
+
+| Input | quoteIdentifier() | quoteIdentifierAfterDot() | quoteIdentifierTypeName() |
+|-------|-------------------|---------------------------|---------------------------|
+| `mytable` | `mytable` | `mytable` | `mytable` |
+| `MyTable` | `"MyTable"` | `"MyTable"` | `"MyTable"` |
+| `json` | `"json"` | `json` | `json` |
+| `int` | `"int"` | `int` | `int` |
+| `boolean` | `"boolean"` | `boolean` | `boolean` |
+| `interval` | `"interval"` | `interval` | `interval` |
+| `select` | `"select"` | `select` | `"select"` |
+| `from` | `"from"` | `from` | `"from"` |
+
+### quoteTypeDottedName(parts: string[])
+
+For schema-qualified type names, use `quoteTypeDottedName()` which applies type-name quoting to all parts:
+
+```typescript
+static quoteTypeDottedName(parts: string[]): string {
+    if (!parts || parts.length === 0) return '';
+    return parts.map(part => QuoteUtils.quoteIdentifierTypeName(part)).join('.');
+}
+```
+
+### Examples
+
+| Input Parts | Output |
+|-------------|--------|
+| `['json']` | `json` |
+| `['myschema', 'json']` | `myschema.json` |
+| `['custom', 'int']` | `custom.int` |
+| `['myapp', 'boolean']` | `myapp.boolean` |
+| `['myschema', 'select']` | `myschema."select"` |
+
+### When to Use Type-Name Quoting
+
+Use `quoteTypeDottedName()` in the `TypeName` handler for non-pg_catalog types. This ensures that user-defined types with keyword names are emitted with minimal quoting.
+
 ## Composition Helpers
 
 ### quoteDottedName(parts: string[])
@@ -359,13 +452,17 @@ When updating to support new PostgreSQL versions, ensure `kwlist.ts` is synchron
 | Dotted name (multi-part) | `quoteDottedName()` | `schema.table`, `schema.function` |
 | Two-part qualified name | `quoteQualifiedIdentifier()` | `schema.table` |
 | After-dot component only | `quoteIdentifierAfterDot()` | Indirection field access |
+| Type name (single or multi-part) | `quoteTypeDottedName()` | `myschema.json`, `custom.int` |
+| Type name component only | `quoteIdentifierTypeName()` | Type name part |
 | String literal | `escape()` or `formatEString()` | String values in SQL |
 
 ## Test Fixtures
 
 The quoting behavior is verified by test fixtures in `__fixtures__/kitchen-sink/pretty/`:
 
 - `quoting-1.sql` through `quoting-7.sql`: Test cases for `faker.float`, `faker.interval`, `faker.boolean`, and `pg_catalog.substring`
+- `quoting-8.sql` through `quoting-13.sql`: Test cases for type casts with `json`, `jsonb`, `boolean`, `interval`, `int`
+- `quoting-14.sql` through `quoting-16.sql`: Test cases for user-defined schema-qualified types with keyword names (`myschema.json`, `custom.int`, `myapp.boolean`)
 
 The corresponding snapshots in `__tests__/pretty/__snapshots__/quoting-pretty.test.ts.snap` demonstrate the expected output with minimal quoting.
 

packages/deparser/__tests__/pretty/__snapshots__/quoting-pretty.test.ts.snap

@@ -50,6 +50,24 @@ $$ LANGUAGE plpgsql"
 
 exports[`non-pretty: pretty/quoting-7.sql 1`] = `"CREATE DOMAIN origin AS text CHECK (value = pg_catalog.substring(value, '^(https?://[^/]*)'))"`;
 
+exports[`non-pretty: pretty/quoting-8.sql 1`] = `"SELECT '{"a":1}'::json"`;
+
+exports[`non-pretty: pretty/quoting-9.sql 1`] = `"SELECT '{"b":2}'::jsonb"`;
+
+exports[`non-pretty: pretty/quoting-10.sql 1`] = `"SELECT CAST(true AS boolean)"`;
+
+exports[`non-pretty: pretty/quoting-11.sql 1`] = `"SELECT '1 day'::interval"`;
+
+exports[`non-pretty: pretty/quoting-12.sql 1`] = `"SELECT 42::int"`;
+
+exports[`non-pretty: pretty/quoting-13.sql 1`] = `"INSERT INTO test_table (data) VALUES ('{"c":3}'::json)"`;
+
+exports[`non-pretty: pretty/quoting-14.sql 1`] = `"SELECT CAST('{"d":4}' AS myschema.json)"`;
+
+exports[`non-pretty: pretty/quoting-15.sql 1`] = `"SELECT CAST(100 AS custom.int)"`;
+
+exports[`non-pretty: pretty/quoting-16.sql 1`] = `"SELECT CAST(true AS myapp.boolean)"`;
+
 exports[`pretty: pretty/quoting-1.sql 1`] = `
 "CREATE FUNCTION faker.float(min double precision DEFAULT 0, max double precision DEFAULT 100) RETURNS double precision AS $$
 BEGIN
@@ -102,3 +120,26 @@ exports[`pretty: pretty/quoting-7.sql 1`] = `
 "CREATE DOMAIN origin AS text 
   CHECK (value = pg_catalog.substring(value, '^(https?://[^/]*)'))"
 `;
+
+exports[`pretty: pretty/quoting-8.sql 1`] = `"SELECT '{"a":1}'::json"`;
+
+exports[`pretty: pretty/quoting-9.sql 1`] = `"SELECT '{"b":2}'::jsonb"`;
+
+exports[`pretty: pretty/quoting-10.sql 1`] = `"SELECT CAST(true AS boolean)"`;
+
+exports[`pretty: pretty/quoting-11.sql 1`] = `"SELECT '1 day'::interval"`;
+
+exports[`pretty: pretty/quoting-12.sql 1`] = `"SELECT 42::int"`;
+
+exports[`pretty: pretty/quoting-13.sql 1`] = `
+"INSERT INTO test_table (
+  data
+) VALUES
+  ('{"c":3}'::json)"
+`;
+
+exports[`pretty: pretty/quoting-14.sql 1`] = `"SELECT CAST('{"d":4}' AS myschema.json)"`;
+
+exports[`pretty: pretty/quoting-15.sql 1`] = `"SELECT CAST(100 AS custom.int)"`;
+
+exports[`pretty: pretty/quoting-16.sql 1`] = `"SELECT CAST(true AS myapp.boolean)"`;

packages/deparser/__tests__/pretty/quoting-pretty.test.ts

@@ -7,6 +7,15 @@ const prettyTest = new PrettyTest([
   'pretty/quoting-5.sql',
   'pretty/quoting-6.sql',
   'pretty/quoting-7.sql',
+  'pretty/quoting-8.sql',
+  'pretty/quoting-9.sql',
+  'pretty/quoting-10.sql',
+  'pretty/quoting-11.sql',
+  'pretty/quoting-12.sql',
+  'pretty/quoting-13.sql',
+  'pretty/quoting-14.sql',
+  'pretty/quoting-15.sql',
+  'pretty/quoting-16.sql',
 ]);
 
 prettyTest.generateTests();

packages/deparser/src/deparser.ts

@@ -1972,8 +1972,9 @@ export class Deparser implements DeparserVisitor {
       }
     }
 
-    const quotedNames = names.map((name: string) => QuoteUtils.quoteIdentifier(name));
-    let result = mods(quotedNames.join('.'), args);
+    // Use type-name quoting for non-pg_catalog types
+    // This allows keywords like 'json', 'int', 'boolean' to remain unquoted in type positions
+    let result = mods(QuoteUtils.quoteTypeDottedName(names), args);
 
     if (node.arrayBounds && node.arrayBounds.length > 0) {
       result += formatArrayBounds(node.arrayBounds);

packages/deparser/src/utils/quote-utils.ts

@@ -185,5 +185,80 @@ export class QuoteUtils {
     }
     return QuoteUtils.quoteIdentifier(ident);
   }
+
+  /**
+   * Quote an identifier that appears as a type name.
+   *
+   * Type names in PostgreSQL have a less strict quoting policy than standalone identifiers.
+   * In type positions, COL_NAME_KEYWORD and TYPE_FUNC_NAME_KEYWORD are allowed unquoted
+   * (e.g., 'json', 'int', 'boolean', 'interval'). Only RESERVED_KEYWORD must be quoted.
+   *
+   * This is different from:
+   * - quoteIdentifier(): quotes all keywords except UNRESERVED_KEYWORD
+   * - quoteIdentifierAfterDot(): only quotes for lexical reasons (no keyword checking)
+   *
+   * Type names still need quoting for lexical reasons (uppercase, special chars, etc.).
+   */
+  static quoteIdentifierTypeName(ident: string): string {
+    if (!ident) return ident;
+
+    let safe = true;
+
+    // Check first character: must be lowercase letter or underscore
+    const firstChar = ident[0];
+    if (!((firstChar >= 'a' && firstChar <= 'z') || firstChar === '_')) {
+      safe = false;
+    }
+
+    // Check all characters
+    for (let i = 0; i < ident.length; i++) {
+      const ch = ident[i];
+      if ((ch >= 'a' && ch <= 'z') ||
+          (ch >= '0' && ch <= '9') ||
+          (ch === '_')) {
+        // okay
+      } else {
+        safe = false;
+      }
+    }
+
+    if (safe) {
+      // For type names, only quote RESERVED_KEYWORD
+      // COL_NAME_KEYWORD and TYPE_FUNC_NAME_KEYWORD are allowed unquoted in type positions
+      const kwKind = keywordKindOf(ident);
+      if (kwKind === 'RESERVED_KEYWORD') {
+        safe = false;
+      }
+    }
+
+    if (safe) {
+      return ident; // no change needed
+    }
+
+    // Build quoted identifier with escaped embedded quotes
+    let result = '"';
+    for (let i = 0; i < ident.length; i++) {
+      const ch = ident[i];
+      if (ch === '"') {
+        result += '"'; // escape " as ""
+      }
+      result += ch;
+    }
+    result += '"';
+
+    return result;
+  }
+
+  /**
+   * Quote a dotted type name (e.g., schema.typename).
+   *
+   * For type names, we use type-name quoting for all parts since the entire
+   * qualified name is in a type context. This allows keywords like 'json',
+   * 'int', 'boolean' to remain unquoted in user-defined schema-qualified types.
+   */
+  static quoteTypeDottedName(parts: string[]): string {
+    if (!parts || parts.length === 0) return '';
+    return parts.map(part => QuoteUtils.quoteIdentifierTypeName(part)).join('.');
+  }
 
 }