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Array Validators

Array validators check array structure (length) and content (uniqueness, sorting) after mutators have been applied.

All Validators​

minLength()
maxLength()
length()
between()
lengthBetween()
unique()
sorted()

Length Validation​

minLength(length)​

Array must have at least the given number of items

v.array(v.string()).minLength(1)
// Input: ["tag1", "tag2"] → Valid ✅
// Input: [] → Invalid ❌

maxLength(length)​

Array must have at most the given number of items

v.array(v.string()).maxLength(10)
// Input: ["tag1", "tag2"] → Valid ✅
// Input: Array with 11+ items → Invalid ❌

length(length)​

Array must have exactly the given number of items

v.array(v.string()).length(5)
// Input: Array with 5 items → Valid ✅
// Input: Array with 4 or 6 items → Invalid ❌

between(min, max)​

Array length must be between min and max (inclusive)

v.array(v.string()).between(1, 10)
// Input: Array with 1-10 items → Valid ✅
// Input: Empty array or 11+ items → Invalid ❌

lengthBetween(min, max)​

Alias for between(). Array length must be between min and max (inclusive)

v.array(v.string()).lengthBetween(1, 10)
// Input: Array with 1-10 items → Valid ✅
// Input: Empty array or 11+ items → Invalid ❌

Content Validation​

unique()​

All array items must be unique

v.array(v.string()).unique()
// Input: ["a", "b", "c"] → Valid ✅
// Input: ["a", "b", "a"] → Invalid ❌

Note: Use onlyUnique() mutator to remove duplicates, or unique() validator to ensure all items are unique.

sorted(direction?)​

Array must be sorted in the specified direction

v.array(v.int()).sorted("asc")
// Input: [1, 2, 3, 4, 5] → Valid ✅
// Input: [1, 3, 2, 4, 5] → Invalid ❌

v.array(v.int()).sorted("desc")
// Input: [5, 4, 3, 2, 1] → Valid ✅
// Input: [5, 3, 4, 2, 1] → Invalid ❌

Parameters:

  • direction (optional): "asc" or "desc" (default: "asc")

Examples​

Tag Validation​

const tagsSchema = v.array(v.string())
  .required()
  .minLength(1)
  .maxLength(10)
  .unique();

const result = await validate(tagsSchema, ["javascript", "typescript"]);
// Result: { isValid: true, data: ["javascript", "typescript"] }

ID Array Validation​

const idsSchema = v.array(v.int())
  .required()
  .between(1, 100)
  .unique();

const result = await validate(idsSchema, [1, 2, 3]);
// Result: { isValid: true, data: [1, 2, 3] }

Exact Length Validation​

const exactSchema = v.array(v.string())
  .required()
  .length(5);

const result = await validate(exactSchema, ["a", "b", "c", "d", "e"]);
// Result: { isValid: true, data: ["a", "b", "c", "d", "e"] }

Sorted Array Validation​

const sortedSchema = v.array(v.int())
  .required()
  .sorted("asc")
  .unique();

const result = await validate(sortedSchema, [1, 2, 3, 4, 5]);
// Result: { isValid: true, data: [1, 2, 3, 4, 5] }

Combined Validation​

const combinedSchema = v.array(v.string())
  .required()
  .minLength(1)
  .maxLength(10)
  .unique()
  .sorted("asc");

const result = await validate(combinedSchema, ["a", "b", "c"]);
// Result: { isValid: true, data: ["a", "b", "c"] }

Unique vs OnlyUnique​

MethodTypePurpose
onlyUnique()MutatorRemove duplicate values
unique()ValidatorEnsure all values are unique

Usage:

// Option 1: Remove duplicates with mutator
v.array(v.string()).onlyUnique()

// Option 2: Validate uniqueness with validator
v.array(v.string()).unique()

// Option 3: Both - remove duplicates then validate
v.array(v.string()).onlyUnique().unique()

See Also​