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📄 predicates.ts

📊 Analysis Summary

Metric	Count
🔧 Functions	11
📦 Imports	2
📊 Variables & Constants	4

📚 Table of Contents

• Imports
• Variables & Constants
• Functions

🛠️ File Location:

📂 packages/type-utils/src/predicates.ts

📦 Imports

Name	Source
debug	debug
isTypeFlagSet	./typeFlagUtils

---

Variables & Constants

Name	Type	Kind	Value	Exported
Nullable	number	const	ts.TypeFlags.Undefined | ts.TypeFlags.Null	✗
ObjectFlagsType	number	const	`ts.TypeFlags.Any
Nullable
ts.TypeFlags.Never
ts.TypeFlags.Object
ts.TypeFlags.Union
ts.TypeFlags.Intersection`	✗
objectTypeFlags	any	const	(type as ts.ObjectType).objectFlags	✗
typeAndBaseTypes	ts.Type[]	const	[type]	✗

---

Functions

isNullableType(type: ts.Type): boolean

Code

export function isNullableType(type: ts.Type): boolean {
  return isTypeFlagSet(
    type,
    ts.TypeFlags.Any |
      ts.TypeFlags.Unknown |
      ts.TypeFlags.Null |
      ts.TypeFlags.Undefined |
      ts.TypeFlags.Void,
  );
}

• JSDoc:

  /**
   * Checks if the given type is (or accepts) nullable
   */
  

• Parameters:

• type: ts.Type
• Return Type: boolean
• Calls:
• isTypeFlagSet (from ./typeFlagUtils)

isTypeArrayTypeOrUnionOfArrayTypes(type: ts.Type, checker: ts.TypeChecker): boolean

Code

export function isTypeArrayTypeOrUnionOfArrayTypes(
  type: ts.Type,
  checker: ts.TypeChecker,
): boolean {
  for (const t of tsutils.unionConstituents(type)) {
    if (!checker.isArrayType(t)) {
      return false;
    }
  }

  return true;
}

• JSDoc:

  /**
   * Checks if the given type is either an array type,
   * or a union made up solely of array types.
   */
  

• Parameters:

• type: ts.Type
• checker: ts.TypeChecker
• Return Type: boolean
• Calls:
• tsutils.unionConstituents
• checker.isArrayType

isTypeNeverType(type: ts.Type): boolean

Code

export function isTypeNeverType(type: ts.Type): boolean {
  return isTypeFlagSet(type, ts.TypeFlags.Never);
}

• JSDoc:

  /**
   * @returns true if the type is `never`
   */
  

• Parameters:

• type: ts.Type
• Return Type: boolean
• Calls:
• isTypeFlagSet (from ./typeFlagUtils)

isTypeUnknownType(type: ts.Type): boolean

Code

export function isTypeUnknownType(type: ts.Type): boolean {
  return isTypeFlagSet(type, ts.TypeFlags.Unknown);
}

• JSDoc:

  /**
   * @returns true if the type is `unknown`
   */
  

• Parameters:

• type: ts.Type
• Return Type: boolean
• Calls:
• isTypeFlagSet (from ./typeFlagUtils)

isTypeReferenceType(type: ts.Type): type is ts.TypeReference

Code

export function isTypeReferenceType(type: ts.Type): type is ts.TypeReference {
  if ((type.flags & ObjectFlagsType) === 0) {
    return false;
  }
  const objectTypeFlags = (type as ts.ObjectType).objectFlags;
  return (objectTypeFlags & ts.ObjectFlags.Reference) !== 0;
}

• Parameters:
• type: ts.Type
• Return Type: type is ts.TypeReference

isTypeAnyType(type: ts.Type): boolean

Code

export function isTypeAnyType(type: ts.Type): boolean {
  if (isTypeFlagSet(type, ts.TypeFlags.Any)) {
    if (type.intrinsicName === 'error') {
      log('Found an "error" any type');
    }
    return true;
  }
  return false;
}

• JSDoc:

  /**
   * @returns true if the type is `any`
   */
  

• Parameters:

• type: ts.Type
• Return Type: boolean
• Calls:
• isTypeFlagSet (from ./typeFlagUtils)
• log

isTypeAnyArrayType(type: ts.Type, checker: ts.TypeChecker): boolean

Code

export function isTypeAnyArrayType(
  type: ts.Type,
  checker: ts.TypeChecker,
): boolean {
  return (
    checker.isArrayType(type) &&
    isTypeAnyType(checker.getTypeArguments(type)[0])
  );
}

• JSDoc:

  /**
   * @returns true if the type is `any[]`
   */
  

• Parameters:

• type: ts.Type
• checker: ts.TypeChecker
• Return Type: boolean
• Calls:
• checker.isArrayType
• isTypeAnyType
• checker.getTypeArguments

isTypeUnknownArrayType(type: ts.Type, checker: ts.TypeChecker): boolean

Code

export function isTypeUnknownArrayType(
  type: ts.Type,
  checker: ts.TypeChecker,
): boolean {
  return (
    checker.isArrayType(type) &&
    isTypeUnknownType(checker.getTypeArguments(type)[0])
  );
}

• JSDoc:

  /**
   * @returns true if the type is `unknown[]`
   */
  

• Parameters:

• type: ts.Type
• checker: ts.TypeChecker
• Return Type: boolean
• Calls:
• checker.isArrayType
• isTypeUnknownType
• checker.getTypeArguments

typeIsOrHasBaseType(type: ts.Type, parentType: ts.Type): boolean

Code

export function typeIsOrHasBaseType(
  type: ts.Type,
  parentType: ts.Type,
): boolean {
  const parentSymbol = parentType.getSymbol();
  if (!type.getSymbol() || !parentSymbol) {
    return false;
  }

  const typeAndBaseTypes = [type];
  const ancestorTypes = type.getBaseTypes();

  if (ancestorTypes) {
    typeAndBaseTypes.push(...ancestorTypes);
  }

  for (const baseType of typeAndBaseTypes) {
    const baseSymbol = baseType.getSymbol();
    if (baseSymbol && baseSymbol.name === parentSymbol.name) {
      return true;
    }
  }

  return false;
}

• JSDoc:

  /**
   * @returns Whether a type is an instance of the parent type, including for the parent's base types.
   */
  

• Parameters:

• type: ts.Type
• parentType: ts.Type
• Return Type: boolean
• Calls:
• parentType.getSymbol
• type.getSymbol
• type.getBaseTypes
• typeAndBaseTypes.push
• baseType.getSymbol

isTypeBigIntLiteralType(type: ts.Type): type is ts.BigIntLiteralType

Code

export function isTypeBigIntLiteralType(
  type: ts.Type,
): type is ts.BigIntLiteralType {
  return isTypeFlagSet(type, ts.TypeFlags.BigIntLiteral);
}

• Parameters:
• type: ts.Type
• Return Type: type is ts.BigIntLiteralType
• Calls:
• isTypeFlagSet (from ./typeFlagUtils)

isTypeTemplateLiteralType(type: ts.Type): type is ts.TemplateLiteralType

Code

export function isTypeTemplateLiteralType(
  type: ts.Type,
): type is ts.TemplateLiteralType {
  return isTypeFlagSet(type, ts.TypeFlags.TemplateLiteral);
}

• Parameters:
• type: ts.Type
• Return Type: type is ts.TemplateLiteralType
• Calls:
• isTypeFlagSet (from ./typeFlagUtils)

---