allow booleans as type discriminators

fixes #98
hoeck · May 9, 2023 · c630956 · c630956
1 parent e447a3b
commit c630956
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Showing 2 changed files with 53 additions and 4 deletions.
diff --git a/src/union.ts b/src/union.ts
@@ -24,7 +24,7 @@ function internalDiscriminatedUnion(
   key: string,
   runtypes: Runtype<any>[],
 ): Runtype<any> {
-  const typeMap = new Map<string | number, Runtype<any>>()
+  const typeMap = new Map<string | number | boolean, Runtype<any>>()
 
   // build an index for fast runtype lookups by literal
   runtypes.forEach((t: any) => {
@@ -37,9 +37,15 @@ function internalDiscriminatedUnion(
       )
     }
 
-    if (!(typeof tagValue === 'string' || typeof tagValue === 'number')) {
+    if (
+      !(
+        typeof tagValue === 'string' ||
+        typeof tagValue === 'number' ||
+        typeof tagValue === 'boolean'
+      )
+    ) {
       throw new RuntypeUsageError(
-        `broken record type definition, ${t}[${key}] must be a string or number, not ${debugValue(
+        `broken record type definition, ${t}[${key}] must be a literal, not ${debugValue(
           tagValue,
         )}`,
       )

diff --git a/test/union.test.ts b/test/union.test.ts
@@ -36,7 +36,7 @@ describe('union', () => {
   })
 })
 
-describe('discriminatedUnion', () => {
+describe('discriminated union', () => {
   enum Tag {
     A = 'a_tag',
     B = 'b_tag',
@@ -129,4 +129,47 @@ describe('discriminatedUnion', () => {
       ),
     ])
   })
+
+  it('should allow numbers and booleans as discrimination literals too', () => {
+    const runtype = st.union(
+      st.record({
+        type: st.literal(1),
+        number: st.number(),
+      }),
+      st.record({ type: st.literal(true), boolean: st.boolean() }),
+      st.record({ type: st.literal('a'), string: st.string() }),
+    )
+
+    expectAcceptValuesPure(runtype, [
+      { type: 1, number: 2 },
+      { type: true, boolean: false },
+      { type: 'a', string: 'b' },
+    ])
+
+    expectRejectValues(runtype, [
+      // incorrect type
+      { type: 1, number: 'foo' },
+      { type: 1, boolean: false },
+      { type: true, boolean: 1 },
+      { type: true, boolean: false, number: 1 },
+      { type: 'a', number: 1 },
+      { type: 'a', string: 'a', boolean: false, number: 1 },
+      { type: 'a', string: false },
+      // non-existing type discriminator
+      { type: 2 },
+      { type: 2, number: 2 },
+      { type: false, boolean: true },
+      { type: false, number: 1 },
+      { type: 'b', string: 'a' },
+      { type: 'c' },
+      { type: '' },
+      // completely missing type literal
+      { type: null },
+      { string: 'b' },
+      {},
+      { number: false },
+      { boolean: 1 },
+      { a: 1 },
+    ])
+  })
 })