Merge pull request #550 from streamich/cbor-dag-float

Always encode floats as 64 bit values in DAG-CBOR

Author: streamich

src/json-pack/cbor/CborEncoderDag.ts

@@ -8,7 +8,7 @@ export class CborEncoderDag extends CborEncoderStable {
   public writeFloat(float: number): void {
     if (float !== float) return this.writeNull();
     if (!Number.isFinite(float)) return this.writeNull();
-    super.writeFloat(float);
+    this.writer.u8f64(0xfb, float);
   }
 
   public writeTag(tag: number, value: unknown): void {

src/json-pack/cbor/__tests__/CborEncoderDag.spec.ts

@@ -99,3 +99,17 @@ describe('only extension = 42 is permitted', () => {
     expect(() => encoder.encode({a: 'a', b: new NotCID('b')})).toThrowError(new Error('Unknown value type'));
   });
 });
+
+describe('floats', () => {
+  test('always encodes floats as double precision 64 bits', () => {
+    const floats = [
+      0.1, 0.2, 0.3, 0.4, 0.5, -0.1, -0.2, -0.3, -0.4, -0.5, 1.1, 1.12, 1.123, 1.1234, 0.12, 0.123, 0.1234,
+    ];
+    const sizes = new Set<number>();
+    for (const float of floats) {
+      const encoded = encoder.encode(float);
+      sizes.add(encoded.length);
+    }
+    expect(sizes.size).toBe(1);
+  });
+});