From e80961d1a18a29bb3865e06035e524927d9a0312 Mon Sep 17 00:00:00 2001
From: Jacob Quinn <quinn.jacobd@gmail.com>
Date: Sun, 4 Oct 2026 13:38:36 -0600
Subject: [PATCH] Validate abstract vector array instances

AI disclosure: This work was prepared with assistance from OpenAI Codex.
---
 src/validation.jl        |  6 +--
 test/runtests.jl         |  1 +
 test/vector_instances.jl | 99 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 103 insertions(+), 3 deletions(-)
 create mode 100644 test/vector_instances.jl

diff --git a/src/validation.jl b/src/validation.jl
index 3e3cb2d..2daa961 100644
--- a/src/validation.jl
+++ b/src/validation.jl
@@ -385,8 +385,8 @@ function _validate(
 end
 
 function _additional_items(x, num_items, val, path)
-    for i in (num_items+1):length(x)
-        ret = _validate_child(x[i], val, path, i)
+    for (i, xi) in enumerate(Iterators.drop(x, num_items))
+        ret = _validate_child(xi, val, path, num_items + i)
         if ret !== nothing
             return ret
         end
@@ -581,7 +581,7 @@ function _validate(
 end
 
 _is_type(::Any, ::Val) = false
-_is_type(::Array, ::Val{:array}) = true
+_is_type(::Union{Array,AbstractVector}, ::Val{:array}) = true
 _is_type(::Bool, ::Val{:boolean}) = true
 _is_type(::Integer, ::Val{:integer}) = true
 _is_type(x::AbstractFloat, ::Val{:integer}) = isinteger(x)
diff --git a/test/runtests.jl b/test/runtests.jl
index da335ba..0664f87 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -15,6 +15,7 @@ import ZipFile
 include("additional_patterns.jl")
 include("integer_floats.jl")
 include("string_instances.jl")
+include("vector_instances.jl")
 
 const TEST_SUITE_URL = "https://github.com/json-schema-org/JSON-Schema-Test-Suite/archive/23.1.0.zip"
 
diff --git a/test/vector_instances.jl b/test/vector_instances.jl
new file mode 100644
index 0000000..cc8a44f
--- /dev/null
+++ b/test/vector_instances.jl
@@ -0,0 +1,99 @@
+struct _OffsetVector{T} <: AbstractVector{T}
+    values::Vector{T}
+end
+Base.size(x::_OffsetVector) = size(x.values)
+Base.axes(x::_OffsetVector) = (0:(length(x.values)-1),)
+Base.getindex(x::_OffsetVector, i::Int) = x.values[i+1]
+Base.iterate(x::_OffsetVector, state...) = iterate(x.values, state...)
+
+@testset "AbstractVector array instances" begin
+    array = JSONSchema.Schema(Dict("type" => "array"))
+    nullable = JSONSchema.Schema(Dict("type" => ["array", "null"]))
+    vectors = ([1, 2, 3], view([0, 1, 2, 3, 0], 2:4), 1:3)
+    for data in (vectors..., BitVector([true, false]))
+        @test isvalid(array, data)
+        @test isvalid(nullable, data)
+        @test isvalid(JSONSchema.schema(typeof(data)), data)
+    end
+    @test isvalid(nullable, nothing)
+
+    for data in vectors
+        for (keyword, constraint, expected) in (
+            ("minItems", 3, true),
+            ("minItems", 4, false),
+            ("maxItems", 3, true),
+            ("maxItems", 2, false),
+            ("uniqueItems", true, true),
+            ("contains", Dict("const" => 2), true),
+            ("contains", Dict("const" => 4), false),
+            ("items", Dict("type" => "integer"), true),
+            ("items", false, false),
+        )
+            schema = JSONSchema.Schema(
+                Dict("type" => "array", keyword => constraint),
+            )
+            @test isvalid(schema, data) == expected
+        end
+        object = JSONSchema.Schema(
+            Dict(
+                "properties" => Dict(
+                    "values" => Dict(
+                        "type" => "array",
+                        "items" => Dict("type" => "integer"),
+                    ),
+                ),
+            ),
+        )
+        @test isvalid(object, Dict("values" => data))
+    end
+
+    integers = JSONSchema.Schema(
+        Dict("type" => "array", "items" => Dict("type" => "integer")),
+    )
+    for data in ([1.0, 1.5, 2.0], view([1.0, 1.5, 2.0], 1:3), 1.0:0.5:2.0)
+        issue = JSONSchema.validate(integers, data)
+        @test issue isa JSONSchema.SingleIssue &&
+              issue.reason == "type" &&
+              JSONSchema.json_pointer(issue) == "#/1"
+    end
+    empty = JSONSchema.Schema(Dict("type" => "array", "maxItems" => 0))
+    for data in (Int[], view(Int[], 1:0), 1:0)
+        @test isvalid(empty, data)
+    end
+    booleans = JSONSchema.Schema(
+        Dict("type" => "array", "items" => Dict("type" => "boolean")),
+    )
+    @test isvalid(booleans, BitVector([true, false]))
+    @test !isvalid(
+        JSONSchema.Schema(Dict("type" => "array", "uniqueItems" => true)),
+        BitVector([true, false, true]),
+    )
+
+    for data in (1, true, "array", nothing, Dict(), (1, 2))
+        @test !isvalid(array, data)
+    end
+    @test isvalid(array, [1 2; 3 4])
+end
+
+@testset "Offset vector additional items use JSON positions" begin
+    integer = Dict("type" => "integer")
+    raw = Dict{String,Any}("items" => [integer], "additionalItems" => integer)
+    for schema in (
+        JSONSchema.Schema(raw),
+        JSONSchema.Schema(merge(raw, Dict("type" => "array"))),
+    )
+        @test isvalid(schema, _OffsetVector([1, 2, 3]))
+        @test isvalid(schema, _OffsetVector(Int[]))
+        issue = JSONSchema.validate(schema, _OffsetVector([1.0, 2.5, 3.0]))
+        @test issue isa JSONSchema.SingleIssue
+        @test issue.x == 2.5
+        @test issue.path == "[2]"
+        @test JSONSchema.json_pointer(issue) == "#/1"
+        issue = JSONSchema.validate(schema, _OffsetVector([1.5, 2.0]))
+        @test JSONSchema.json_pointer(issue) == "#/0"
+    end
+    @test isvalid(
+        JSONSchema.schema(_OffsetVector{Int}),
+        _OffsetVector([1, 2, 3]),
+    )
+end