CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

Unreleased

3.1.0

Added

• Newly exports the following types: Assign, If, IsUnion, ObjectType, PartialObjectSchema, StructSchema, TupleSchema (#25)

3.0.0

Added

• Newly exports the following types: AnyStruct, EnumSchema, InferStructTuple, IsExactMatch, IsMatch, IsRecord, IsTuple, ObjectSchema, OmitBy, Optionalize, PickBy, Simplify, UnionToIntersection (#18).

Fixed

• BREAKING: Expose separate build entry points and type declarations for CommonJS and ESM via package manifest exports. (#18)

2.0.0

Changed

• Prepare package for releasing under @metamask organisation (#1, #3, #4, #5, #6, #7, #8, #12, #15)
  • The package name is now @metamask/superstruct.
  • The changelog file has been renamed to CHANGELOG.md, and the format has changed to fit MetaMask's changelog style.

Fixed

• BREAKING: Expose CommonJS and ESM builds via package manifest exports (#5)
  • It's no longer possible to import files from the dist folder directly.

1.0.0

Added

• Add an optional message argument to override error messages.
  • You can now pass in a message argument to all of the error checking functions which will override any error message with your own message. If you do, Superstruct's original descriptive message will still be accessible via error.cause.
  • For example:

    assert(data, User, "The user is invalid!");
    // StructError: The user is invalid!

0.16.0

Changed

• BREAKING: Refinement functions are now called with valid, but potentially unrefined values.
  • Previously the functions passed in to refine would always be called with sub-elements (e.g., when using objects or arrays) that were completely valid and refined. However, this prevented collecting all the refinement errors from subelements in a validation in one go, which is common when validating forms. Note: this should not have any effect on almost all use cases, so you're safe to upgrade.

0.15.0

Fixed

• Unions can now be coerced.
  • Previously unions created a barrier in coercion such that structs nested inside unions would not have their coercion logic triggered, but this has been fixed.
• Assigning preserves type structs.
  • Previously using the assign helper would implicitly convert type structs into object structs which wasn't expected and confusing, but this has been fixed.

0.14.0

Changed

• BREAKING: The mask helper now works for nested objects.
  • Previously it would only mask the properties at the top-level of a struct, however now it acts deeply. You can use it to define object structs once, but use them either strictly or loosely.
• BREAKING: The masked coercion has been removed.
  • This previously allowed you to mix in masking to a specific struct, but the mask helper is a more robust way to do this, and it doesn't force you to maintain two separate structs.

0.13.0

Added

• Structs can now define an entries iterator for nested values.
  • Previously iterating through nested values was defined in a one-off manner inside certain structs, but this led to non-uniform support. Now, any struct can define an entries iterator that will cause nested values to be automatically coerced and validated.
• Coercion receives context objects and supports nested values.
  • Previously context objects were only passed to the validations and refinements. But the same context is passed to coercions too so you can implement more complex logic. And coercions are automatically applied to nested values thanks to the addition of entries.

Changed

• Iteration logic has gotten simpler, and more performant.
  • The addition of the entries logic has enabled us to only ever iterate through a tree of values one time for coercion and validation, instead of once each. This should speed up most standard use cases.

Removed

• BREAKING: The ctx.fail() function has been removed.
  • Previously you'd use it to return more information about a failure inside a struct. Now you can simply return a partial failure object.
• BREAKING: The ctx.check() function has been removed.
  • Previously you'd use it to validate nested objects in more complex struct shapes. Now you can use the new entries property for this instead.
• BREAKING: The context.struct and context.value properties have been removed.
  • These properties were previously available, but unnecessary since anywhere you have the context object you will also know the value and the specific struct that is being validated. Keeping them around required extra unnecessary plumbing in the library that made composing structs much more difficult, so they were removed.

0.12.0

Added

• New Describe utility type.

  • This new utility lets you define a struct from an existing TypeScript type and ensure that the struct's validation matches it, otherwise TypeScript's compiler will error. For example:

    type User = {
      id: number;
      name: string;
    };
    
    const User: Describe<User> = object({
      id: string(), // This mistake will fail to pass type checking!
      name: string(),
    });

Changed

• BREAKING: The coerce helper has changed to be more type-safe.

  • Previously coerce functions were called with value: unknown because they ran before all validation. However, now they take a new second argument that is another struct to narrow the cases where coercions occurs. This means the value for coercion will now be type-safe.

  • For example:

    // Previously
    const MyNumber = coerce(number(), (value) => {
      return typeof value === "string" ? parseFloat(value) : value;
    });
    
    // Now
    const MyNumber = coerce(number(), string(), (value) => {
      return parseFloat(value);
    });

0.11.0

Added

• New assign, pick, and omit object utilities.

  • These utilities make composing object structs together possible, which should make re-using structs in your codebase easier.

  • For example:

    // Combine two structs with `assign`:
    const a = object({ id: number() });
    const b = object({ name: string() });
    const c = assign([a, b]);
    
    // Pick out specific properties with `pick`:
    const a2 = pick(c, ["id"]);
    
    // Omit specific properties with `omit`:
    const a3 = omit(c, ["name"]);

• New unknown struct.

  • This is the same as the existing any struct, but it will ensure that in TypeScript the value is of the more restrictive unknown type, so it encourages better type safety.
  • For example:

    const Shape = type({
      id: number(),
      name: string(),
      other: unknown(),
    });

• New integer, regexp, and func structs.

  • These are just simple additions for common use cases of ensuring a value is an integer, a regular expression object (not a string!), or a function.
  • For example:

    const Shape = type({
      id: integer(),
      matches: regexp(),
      send: func(),
    });

• New max/min refinements.

  • For refining number (or integer) or date structs to ensure they are greater than or less than a specific threshold. The third argument can indicate whether to make the threshold exclusive (instead of the default inclusive).
  • For example:

    const Index = min(number(), 0);
    const PastOrPresent = max(date(), new Date());
    const Past = max(date(), new Date(), { exclusive: true });

• Even more information on errors.

  • Errors now expose the error.refinement property when the failure originated in a refinement validation. And they also now have an error.key property which is the key for the failure in the case of complex values like arrays/objects. (Previously the key was retrievable by checking error.path, but this will make the 90% case easier.)

Changed

• BREAKING: The coerce helper has been renamed to create.

  • This will hopefully make it more clear that it's fully coercing and validating a value against a struct, throwing errors if the value was invalid. This has caused confusion for people who though it would just coerce the value and return the unvalidated-but-coerced version.

  • For example:

    // Previously
    const user = coerce(data, User);
    
    // Now
    const user = create(data, User);

• BREAKING: The struct, refinement and coercion factories have been renamed.

  • This renaming is purely for keeping things slightly cleaner and easier to understand. The new names are define, refine, and coerce. Separating them slightly from the noun-based names used for the types themselves.

  • For example:

    // Previously
    const Email = struct('email', isEmail)
    const Positive = refinement('positive', number(), n => n > 0)
    const Trimmed = coercion(string(), s => s.trim()
    
    // Now
    const Email = define('email', isEmail)
    const Positive = refine(number(), 'positive', n => n > 0)
    const Trimmed = coerce(string(), s => s.trim())

• BREAKING: The length refinement has been renamed to size.

  • This is to match with the expansion of it's abilities from purely strings and arrays to also now include numbers, maps, and sets. In addition you can also omit the max argument to specify an exact size:

  • For example:

    // Previously
    const Name = length(string(), 1, 100);
    const MyArray = length(array(string()), 3, 3);
    
    // Now
    const Name = size(string(), 1, 100);
    const MyArray = size(array(string()), 3);
    const Id = size(integer(), 1, Infinity);
    const MySet = size(set(), 1, 9);

• BREAKING: The StructType inferring helper has been renamed to Infer.

  • This just makes it slightly easier to read what's going on when you're inferring a type.

  • For example:

    // Previously
    type User = StructType<typeof User>;
    
    // Now
    type User = Infer<typeof User>;

• BREAKING: The error.type property has been standardized.

  • Previously it was a human-readable description that sort of incorporated the schema. Now it is simple the plain lowercase name of the struct in question, making it something you can use programmatically when formatting errors.

  • For example:

    // Previously
    "Array<string>";
    "[string,number]";
    "Map<string,number>";
    
    // Now
    "array";
    "tuple";
    "map";

0.10.0

Changed

• BREAKING: All types are created from factories.

  • Previously depending on whether the type was a complex type or a scalar type they'd be defined different. Complex types used factories, whereas scalars used strings. Now all types are exposed as factories.

  • For example:

    // Previously
    const User = struct.object({
      name: "string",
      age: "number",
    });
    
    // Now
    const User = object({
      name: string(),
      age: number(),
    });

• BREAKING: Custom scalars are no longer pre-defined as strings.

  • Previously, you would define all of your "custom" types in a single place in your codebase and then refer to them in structs later on with a string value. This worked, but added a layer of unnecessary indirection, and made it impossible to accomodate runtime type signatures.

  • For example:

    // Previously
    const struct = superstruct({
      types: {
        email: isEmail,
      },
    });
    
    const Email = struct("email");
    
    // Now
    const Email = struct("email", isEmail);

• BREAKING: Coercion is now separate from validation.

  • Previously there was native logic for handling default values for structs when validating them. This has been abstracted into the ability to define any custom coercion logic for structs, and it has been separate from validation to make it very clear when data can change and when it cannot.
  • For example:

    const output = User.assert(input);
    // Would now be:
    const input = coerce(input, User);

• BREAKING: Validation context is now a dictionary of properties.

  • Previously when performing complex validation logic that was dependent on other properties on the root object, you could use the second branch argument to the validation function. This argument has been changed to be a context dictionary with more information. The same branch argument can now be accessed as context.branch, along with the new information.

• BREAKING: Unknown properties of objects now have a 'never' type.

  • Previously unknown properties would throw errors with type === null, however the newly introduced 'never' type is now used instead.

• BREAKING: Defaults are now defined with a separate coercion helper.

  • Previously all structs took a second argument that defined the default value to use if an undefined value was present. This has been pulled out into a separate helper now to clearly distinguish coercion logic.

  • For example:

    const Article = struct.object(
      {
        title: "string",
      },
      {
        title: "Untitled",
      }
    );
    
    // Now
    const Article = defaulted(
      object({
        title: string(),
      }),
      {
        title: "Untitled",
      }
    );

• BREAKING: Optional arguments are now defined with a separate factory.

  • Similarly to defaults, there is a new optional factory for defined values that can also be undefined.

  • For example:

    const Flag = struct("string?");
    
    // Now
    const Flag = optional(string());

• BREAKING: Several structs have been renamed.

  • This was necessary because structs are now exposed directly as variables, which runs afoul of reserved words. So the following renames have been applied:
    • interface -> type
    • enum -> enums
    • function -> func

0.8.0

Added

• Superstruct is now written in TypeScript.
  • It was rewritten from the ground up to make use of types, and to have better inline documented if you use a TypeScript-compatible IDE. There are probably improvements that can be made, so if you'd like to contribute please do!
• A new partial struct mimics TypeScript's Partial utility.
  • The new struct validates that its input partially matches an object defined as a set of properties with associated types. All of the properties of the object are optional.
• A new size struct allows validating array and string lengths.
  • The new struct validates that its input has a certain size, by checking its length property. This works strings or arrays.
• You can now provide a custom Error setting.
  • By passing in your own constructor when configuring Superstruct you can have complete control over the exact errors that are generated by structs that fail validation.

Changed

• BREAKING: Several structs have been renamed.
  • Superstruct tries to mimic established naming schemes whenever possible for its API, and TypeScript is one of our main comparisons. To make things easier for people, we've renamed a few structs to more closely match their TypeScript counterparts:
    • The list struct is now called array.
    • The partial struct is now called pick.
    • The dict struct is now called record.
• BREAKING: The interface struct now returns the original, unaltered value!
  • In an effort to make things more familiar, the interface struct now always returns the object that it is called with when it passes validation. So if the object was a function, a function will be returned. This makes it match more closely with the idea of "structural typing" that TypeScript and other typing systems are based on. If you want the old behavior, use the pick struct.
• BREAKING: Computed values function signatures have changed!
  • Previously a computed value would be called with a signature of (value, root) in some cases and (value, parent) in others. This was confusing, and the cause for the inconsistency was complex. This logic has been simplified, and now computed values are called with (value, branch, path) in all cases.
  • For example:

    struct.dynamic((value, branch, path) => {
      value === branch[branch.length - 1]; // you can get the value...
      const parent = branch[branch.length - 2]; // ...and the parent...
      const key = path[path.length - 1]; // ...and the key...
      value === parent[key];
      const root = branch[0]; // ...and the root!
    });

• BREAKING: The error.errors property has been renamed error.failures, and isn't cyclical.
  • It being cyclical caused lots of issues whenever an StructError object was attempted to be serialized. And the errors property was slightly confusing because the elements of the array weren't full error objects. The new structure is easier to understand and work with.
• BREAKING: The error.reason property is no longer special-cased.
  • Previously you could return a "reason" string from validator functions and it would be added to error objects. However, now you must return an error properties object (with a reason property if you'd like), and all of the properties will be added to the error object. This makes Superstruct even more flexible as far as custom error details go.
• The type property of structs have been rewritten to be more clear.
  • This is an implementation mostly, but the struct.type string which shows up in error messages have been tweaked to be slightly more clear exactly what type they are checking for.

Removed

• BREAKING: The enums struct has been removed.
  • This was special-cased in the API previously, but you can get the exact same behavior by creating it using the array and enum structs:

    struct.array(struct.enum(["red", "blue", "green"]));

• BREAKING: The any struct has been removed! (Not the scalar though.)
  • Previously struct.any() was exposed that did the same thing as struct(), allowing you to use shorthands for common structs. But this was confusingly named because it has nothing to do with the 'any' scalar type. And since it was redundant it has been removed.

0.7.0

Changed

• BREAKING: The build process now outputs ES5 code.
  • Previously it was outputting ES6 code, which posed problems for some builders. This change shouldn't really affect anyone negatively, but it's being released as a breaking version just in case.

0.6.0

Changed

• BREAKING: Invalid Date objects are now considered invalid.
  • Previously using the built-in 'date' validator would only check that the object was a Date instance, and not that it was a valid one. This has been fixed, and although it is technically a breaking change, most everyone would have expected this behavior to begin with.

0.5.0

Added

• Errors can now contain reason information.
  • Validator functions can now return string instead of a boolean, denoting the reason a value was invalid. This can then be used to create more helpful error messages.

Changed

• BREAKING: Validators must now return true, false or an error reason string.
  • Previously any truthy value would be considered valid. Now you can provide more information for the thrown errors by providing a string which will be attached as error.reason. However, this means that truthy string values now equate to invalid, not valid.
• BREAKING: Property validators now receive data as their second argument.
  • Previously you only had access to the property value, but now you also have access to the entire object's data.

0.4.0

Added

• Added the dict, enum, intersection, union and tuple structs.
  • These are all available as struct.dict, struct.enum, etc.

Changed

• BREAKING: object structs are no longer optional-ish.
  • Previously object struct types would not throw if undefined was passed and no properties were required. This was not only confusing, but complex to maintain. Now if you want an object struct to be optional, use the struct.optional(...) helper.

Removed

• Removed the Struct.default method.
  • If you need to get the default value, use the Struct.validate or Struct.assert methods' return value instead.

0.3.0

Changed

• BREAKING: The validate method now returns [ error, result ].
  • Previously it only had a single return value, which necessitated extra type checking to see if the value was an error or a result. Now you can just destructure the array to get either return value, for easier coding.
• Errors have been simplified, removing "codes".
  • Previously there were multiple types of errors that were thrown and you could differentiate between them with the error.code property. But the other properties of the error already let you infer the code, so having multiple types of errors made for a larger API surface without much benefit.

0.2.0

Added

• The basic case is now Struct(data).
  • Previously you had to use Struct.assert(data). Although the assert method (and others) are still there, the basic case is a bit terser and more similar to the struct-initializing APIs in other languages.

Changed

• BREAKING: Structs are now functions again.
  • They are built on the same underlying schema classes underneath though, since that helps the code structure. But to allow for the struct = Struct({ ... }) syntax the structs themselves have changed to be function.

0.1.0

Changed

• BREAKING: Structs are now classes instead of functions.
  • This is better in terms of the API being a bit less magic-y. It's also useful so that we can add other helpful methods to structs besides the assert method. What was previously struct(data) is now struct.assert(data).

0.0.1

Added

• Initial release.