From 460cee9a8f4a874f6373e44549c49d1c63b10109 Mon Sep 17 00:00:00 2001
From: chenyan-dfinity <yan.chen@dfinity.org>
Date: Fri, 10 Apr 2020 13:21:25 -0700
Subject: [PATCH] feat(userlib): add float64 support

---
 src/userlib/js/package.json    |  2 +-
 src/userlib/js/src/idl.test.ts | 15 ++++++++++++
 src/userlib/js/src/idl.ts      | 42 ++++++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/src/userlib/js/package.json b/src/userlib/js/package.json
index ae1cb82d4d..13acb24be4 100644
--- a/src/userlib/js/package.json
+++ b/src/userlib/js/package.json
@@ -9,7 +9,7 @@
     "ci": "npm run prettier && npm run lint && npm run build && npm run test",
     "lint": "tslint --project tsconfig.json --config tslint.json",
     "lint:fix": "npm run lint -- --fix",
-    "prettier": "npx prettier --check src/**/*.ts bootstrap/**/*.ts",
+    "prettier": "npx prettier --check src/*.ts src/**/*.ts bootstrap/*.ts bootstrap/**/*.ts",
     "prettier:write": "npm run prettier -- --write",
     "test": "jest --verbose"
   },
diff --git a/src/userlib/js/src/idl.test.ts b/src/userlib/js/src/idl.test.ts
index 6ad257548f..72c9654f5f 100644
--- a/src/userlib/js/src/idl.test.ts
+++ b/src/userlib/js/src/idl.test.ts
@@ -86,6 +86,21 @@ test('IDL encoding (nat)', () => {
   expect(() => IDL.encode([IDL.Nat], [-1])).toThrow(/Invalid nat argument/);
 });
 
+test('IDL encoding (float64)', () => {
+  // Float64
+  test_(IDL.Float64, 3, '4449444c0001720000000000000840', 'Float');
+  test_(IDL.Float64, 6, '4449444c0001720000000000001840', 'Float');
+  test_(IDL.Float64, 0.5, '4449444c000172000000000000e03f', 'Float');
+  test_(IDL.Float64, Number.NaN, '4449444c000172010000000000f07f', 'NaN');
+  test_(IDL.Float64, Number.POSITIVE_INFINITY, '4449444c000172000000000000f07f', '+infinity');
+  test_(IDL.Float64, Number.NEGATIVE_INFINITY, '4449444c000172000000000000f0ff', '-infinity');
+  test_(IDL.Float64, Number.EPSILON, '4449444c000172000000000000b03c', 'eps');
+  test_(IDL.Float64, Number.MIN_VALUE, '4449444c0001720100000000000000', 'min_value');
+  test_(IDL.Float64, Number.MAX_VALUE, '4449444c000172ffffffffffffef7f', 'max_value');
+  test_(IDL.Float64, Number.MIN_SAFE_INTEGER, '4449444c000172ffffffffffff3fc3', 'min_safe_integer');
+  test_(IDL.Float64, Number.MAX_SAFE_INTEGER, '4449444c000172ffffffffffff3f43', 'max_safe_integer');
+});
+
 test('IDL encoding (fixed-width number)', () => {
   // Fixed-width number
   test_(IDL.Int8, 0, '4449444c00017700', 'Int8');
diff --git a/src/userlib/js/src/idl.ts b/src/userlib/js/src/idl.ts
index 078ba293be..0c9a7e837d 100644
--- a/src/userlib/js/src/idl.ts
+++ b/src/userlib/js/src/idl.ts
@@ -21,6 +21,7 @@ const enum IDLTypeIds {
   Bool = -2,
   Nat = -3,
   Int = -4,
+  Float64 = -14,
   Text = -15,
   Empty = -17,
   Opt = -18,
@@ -111,6 +112,9 @@ export abstract class Visitor<D, R> {
   public visitNat(t: NatClass, data: D): R {
     return this.visitPrimitive(t, data);
   }
+  public visitFloat(t: FloatClass, data: D): R {
+    return this.visitPrimitive(t, data);
+  }
   public visitFixedInt(t: FixedIntClass, data: D): R {
     return this.visitPrimitive(t, data);
   }
@@ -412,6 +416,42 @@ export class NatClass extends PrimitiveType<BigNumber> {
   }
 }
 
+/**
+ * Represents an IDL Float
+ */
+export class FloatClass extends PrimitiveType<number> {
+  public accept<D, R>(v: Visitor<D, R>, d: D): R {
+    return v.visitFloat(this, d);
+  }
+
+  public covariant(x: any): x is number {
+    return typeof x === 'number' || x instanceof Number;
+  }
+
+  public encodeValue(x: number) {
+    const buf = Buffer.allocUnsafe(8);
+    buf.writeDoubleLE(x, 0);
+    return buf;
+  }
+
+  public encodeType() {
+    return slebEncode(IDLTypeIds.Float64);
+  }
+
+  public decodeValue(b: Pipe) {
+    const x = b.read(8);
+    return x.readDoubleLE(0);
+  }
+
+  get name() {
+    return 'float64';
+  }
+
+  public valueToString(x: number) {
+    return x.toString();
+  }
+}
+
 /**
  * Represents an IDL fixed-width Int(n)
  */
@@ -1189,6 +1229,8 @@ export const Text = new TextClass();
 export const Int = new IntClass();
 export const Nat = new NatClass();
 
+export const Float64 = new FloatClass();
+
 export const Int8 = new FixedIntClass(8);
 export const Int16 = new FixedIntClass(16);
 export const Int32 = new FixedIntClass(32);