feat: support readonly types

Author: holvonixAdvay

README.md

@@ -52,6 +52,7 @@ Currently supports (and their nested closure):
 * `t.keyof`
 * `t.tuple`
 * `t.exact`
+* `t.readonly`
 
 ## Use Cases
 

src/core/core.ts

@@ -19,13 +19,13 @@ export type BasicType =
   | t.KeyofType<{ [key: string]: unknown }>
   | t.TupleType<t.Mixed[]>
   | t.ExactType<t.Mixed>
+  | t.ReadonlyType<t.Mixed>
   // not yet supported:
   | t.AnyArrayType
   | t.AnyDictionaryType
   | t.RefinementType<t.Mixed>
   | t.RecursiveType<t.Mixed>
   | t.DictionaryType<t.Mixed, t.Mixed>
-  | t.ReadonlyType<t.Mixed>
   | t.ReadonlyArrayType<t.Mixed>;
 
 export type basicFuzzGenerator<
@@ -171,6 +171,18 @@ export function fuzzExact(b: t.ExactC<t.HasProps>): ConcreteFuzzer<unknown> {
   };
 }
 
+export function fuzzReadonly(
+  b: t.ReadonlyType<t.Any>
+): ConcreteFuzzer<unknown> {
+  return {
+    children: [b.type],
+    func: (n, h0) => {
+      const r = h0.encode(n);
+      return Object.freeze(r);
+    },
+  };
+}
+
 export const defaultMaxArrayLength = 13;
 
 const fuzzArrayWithMaxLength = (maxLength: number = defaultMaxArrayLength) => (
@@ -317,6 +329,7 @@ export const coreFuzzers = [
   partialFuzzer(),
   arrayFuzzer(),
   gen(fuzzExact, 'ExactType'),
+  gen(fuzzReadonly, 'ReadonlyType'),
   gen(fuzzUnion, 'UnionType'),
   gen(fuzzIntersection, 'IntersectionType'),
   gen(fuzzLiteral, 'LiteralType'),

test/helpers.ts

@@ -15,18 +15,6 @@ export const types = [
   t.exact(t.type({ s: t.string, m: t.number, ___0000_extra_: t.string })),
   t.exact(t.partial({ s: t.string, m: t.number })),
   t.exact(t.partial({ s: t.string, m: t.number, ___0000_extra_: t.boolean })),
-  t.exact(
-    t.intersection([
-      t.type({ s: t.string, m: t.number, ___0000_extra_: t.boolean }),
-      t.type({ s: t.string, j: t.boolean }),
-    ])
-  ),
-  t.exact(
-    t.intersection([
-      t.type({ s: t.string, m: t.number, ___0000_extra_: t.boolean }),
-      t.type({ s2: t.string, j: t.boolean }),
-    ])
-  ),
   t.null,
   t.undefined,
   t.void,
@@ -45,7 +33,42 @@ export const types = [
     0.3: null,
   }),
   t.tuple([t.number, t.string, t.boolean]),
+  t.readonly(t.string),
+  t.readonly(t.tuple([t.string, t.boolean])),
+  t.readonly(t.type({ s: t.string, j: t.boolean })),
   // Complex types
+  t.exact(
+    t.intersection([
+      t.type({ s: t.string, m: t.number, ___0000_extra_: t.boolean }),
+      t.type({ s: t.string, j: t.boolean }),
+    ])
+  ),
+  t.exact(
+    t.intersection([
+      t.type({ s: t.string, m: t.number, ___0000_extra_: t.boolean }),
+      t.type({ s2: t.string, j: t.boolean }),
+    ])
+  ),
+  t.readonly(
+    t.intersection([
+      t.type({ s: t.string, m: t.number, ___0000_extra_: t.boolean }),
+      t.type({ s: t.string, j: t.boolean }),
+    ])
+  ),
+  t.exact(
+    t.intersection([
+      t.readonly(
+        t.type({ s: t.string, m: t.number, ___0000_extra_: t.boolean })
+      ),
+      t.type({ s2: t.string, j: t.boolean }),
+    ])
+  ),
+  t.exact(
+    t.intersection([
+      t.type({ s: t.string, m: t.number, ___0000_extra_: t.boolean }),
+      t.readonly(t.type({ s2: t.string, j: t.boolean })),
+    ])
+  ),
   t.intersection([
     t.type({ s: t.string, m: t.number, ___0000_extra_: t.boolean }),
     t.type({ s: t.string, j: t.boolean }),
@@ -78,6 +101,22 @@ export const types = [
     t.partial({ s: t.string, m: t.number, ___0000_extra_: t.boolean }),
     t.partial({ s2: t.string, j: t.boolean }),
   ]),
+  t.union([
+    t.readonly(
+      t.partial({ s: t.string, m: t.number, ___0000_extra_: t.boolean })
+    ),
+    t.readonly(t.partial({ s: t.string, j: t.boolean })),
+  ]),
+  t.union([
+    t.readonly(
+      t.partial({ s: t.string, m: t.number, ___0000_extra_: t.boolean })
+    ),
+    t.readonly(t.partial({ s2: t.string, j: t.boolean })),
+  ]),
+  t.union([
+    t.readonly(t.partial({ s: t.string, m: t.number })),
+    t.readonly(t.partial({ s2: t.string, j: t.boolean })),
+  ]),
   t.type({ s: t.string, m: t.type({ n: t.Int }) }),
   t.type({
     s: t.union([t.string, t.number, t.partial({ n: t.number, z: t.string })]),