add BigInt.fromString and BigInt.fromNumber (#2399)

.changeset/sixty-news-begin.md

@@ -0,0 +1,5 @@
+---
+"effect": patch
+---
+
+add BigInt.fromString and BigInt.fromNumber

packages/effect/src/BigInt.ts

@@ -547,14 +547,89 @@ export const multiplyAll = (collection: Iterable<bigint>): bigint => {
 }
 
 /**
- * Convers a bigint into a number
+ * Takes a `bigint` and returns an `Option` of `number`.
+ *
+ * If the `bigint` is outside the safe integer range for JavaScript (`Number.MAX_SAFE_INTEGER`
+ * and `Number.MIN_SAFE_INTEGER`), it returns `Option.none()`. Otherwise, it converts the `bigint`
+ * to a number and returns `Option.some(number)`.
+ *
+ * @param b - The `bigint` to be converted to a `number`.
+ *
+ * @example
+ * import { toNumber } from "effect/BigInt"
+ * import { Option } from "effect"
+ *
+ * assert.deepStrictEqual(toNumber(BigInt(42)), Option.some(42))
+ * assert.deepStrictEqual(toNumber(BigInt(Number.MAX_SAFE_INTEGER) + BigInt(1)), Option.none())
+ * assert.deepStrictEqual(toNumber(BigInt(Number.MIN_SAFE_INTEGER) - BigInt(1)), Option.none())
  *
- * @since 2.0.0
  * @category conversions
+ * @since 2.0.0
  */
 export const toNumber = (b: bigint): Option.Option<number> => {
   if (b > BigInt(Number.MAX_SAFE_INTEGER) || b < BigInt(Number.MIN_SAFE_INTEGER)) {
     return Option.none()
   }
   return Option.some(Number(b))
 }
+
+/**
+ * Takes a string and returns an `Option` of `bigint`.
+ *
+ * If the string is empty or contains characters that cannot be converted into a `bigint`,
+ * it returns `Option.none()`, otherwise, it returns `Option.some(bigint)`.
+ *
+ * @param s - The string to be converted to a `bigint`.
+ *
+ * @example
+ * import { fromString } from "effect/BigInt"
+ * import { Option } from "effect"
+ *
+ * assert.deepStrictEqual(fromString("42"), Option.some(BigInt(42)))
+ * assert.deepStrictEqual(fromString(" "), Option.none())
+ * assert.deepStrictEqual(fromString("a"), Option.none())
+ *
+ * @category conversions
+ * @since 2.4.12
+ */
+export const fromString = (s: string): Option.Option<bigint> => {
+  try {
+    return s.trim() === ""
+      ? Option.none()
+      : Option.some(BigInt(s))
+  } catch (_) {
+    return Option.none()
+  }
+}
+
+/**
+ * Takes a number and returns an `Option` of `bigint`.
+ *
+ * If the number is outside the safe integer range for JavaScript (`Number.MAX_SAFE_INTEGER`
+ * and `Number.MIN_SAFE_INTEGER`), it returns `Option.none()`. Otherwise, it attempts to
+ * convert the number to a `bigint` and returns `Option.some(bigint)`.
+ *
+ * @param n - The number to be converted to a `bigint`.
+ *
+ * @example
+ * import { fromNumber } from "effect/BigInt"
+ * import { Option } from "effect"
+ *
+ * assert.deepStrictEqual(fromNumber(42), Option.some(BigInt(42)))
+ * assert.deepStrictEqual(fromNumber(Number.MAX_SAFE_INTEGER + 1), Option.none())
+ * assert.deepStrictEqual(fromNumber(Number.MIN_SAFE_INTEGER - 1), Option.none())
+ *
+ * @category conversions
+ * @since 2.4.12
+ */
+export const fromNumber = (n: number): Option.Option<bigint> => {
+  if (n > Number.MAX_SAFE_INTEGER || n < Number.MIN_SAFE_INTEGER) {
+    return Option.none()
+  }
+
+  try {
+    return Option.some(BigInt(n))
+  } catch (_) {
+    return Option.none()
+  }
+}

packages/effect/src/Number.ts

@@ -400,7 +400,7 @@ export const sumAll = (collection: Iterable<number>): number => {
  * @param collection - The collection of `number`s to multiply.
  *
  * @example
- * import { multiplyAll } from 'effect/Number'
+ * import { multiplyAll } from "effect/Number"
  *
  * assert.deepStrictEqual(multiplyAll([2, 3, 4]), 24)
  *

packages/effect/test/BigInt.test.ts

@@ -142,7 +142,43 @@ describe("BigInt", () => {
   })
 
   it("toNumber", () => {
-    assert.deepStrictEqual(BigInt_.toNumber(1n), Option.some(1))
-    assert.deepStrictEqual(BigInt_.toNumber(BigInt(Number.MAX_SAFE_INTEGER) + 1n), Option.none())
+    assert.deepStrictEqual(BigInt_.toNumber(BigInt(Number.MAX_SAFE_INTEGER)), Option.some(Number.MAX_SAFE_INTEGER))
+    assert.deepStrictEqual(BigInt_.toNumber(BigInt(Number.MAX_SAFE_INTEGER) + BigInt(1)), Option.none())
+    assert.deepStrictEqual(BigInt_.toNumber(BigInt(Number.MIN_SAFE_INTEGER)), Option.some(Number.MIN_SAFE_INTEGER))
+    assert.deepStrictEqual(BigInt_.toNumber(BigInt(Number.MIN_SAFE_INTEGER) - BigInt(1)), Option.none())
+    assert.deepStrictEqual(BigInt_.toNumber(BigInt(0)), Option.some(0))
+    assert.deepStrictEqual(BigInt_.toNumber(BigInt(42)), Option.some(42))
+    assert.deepStrictEqual(BigInt_.toNumber(BigInt(-42)), Option.some(-42))
+  })
+
+  it("fromString", () => {
+    assert.deepStrictEqual(BigInt_.fromString("NaN"), Option.none())
+    assert.deepStrictEqual(BigInt_.fromString("Infinity"), Option.none())
+    assert.deepStrictEqual(BigInt_.fromString("-Infinity"), Option.none())
+    assert.deepStrictEqual(BigInt_.fromString("3.14"), Option.none())
+    assert.deepStrictEqual(BigInt_.fromString("-3.14"), Option.none())
+    assert.deepStrictEqual(BigInt_.fromString("1e3"), Option.none())
+    assert.deepStrictEqual(BigInt_.fromString("1e-3"), Option.none())
+    assert.deepStrictEqual(BigInt_.fromString(""), Option.none())
+    assert.deepStrictEqual(BigInt_.fromString("a"), Option.none())
+    assert.deepStrictEqual(BigInt_.fromString("42"), Option.some(BigInt(42)))
+    assert.deepStrictEqual(BigInt_.fromString("\n\r\t 42 \n\r\t"), Option.some(BigInt(42)))
+  })
+
+  it("fromNumber", () => {
+    assert.deepStrictEqual(BigInt_.fromNumber(Number.MAX_SAFE_INTEGER), Option.some(BigInt(Number.MAX_SAFE_INTEGER)))
+    assert.deepStrictEqual(BigInt_.fromNumber(Number.MAX_SAFE_INTEGER + 1), Option.none())
+    assert.deepStrictEqual(BigInt_.fromNumber(Number.MIN_SAFE_INTEGER), Option.some(BigInt(Number.MIN_SAFE_INTEGER)))
+    assert.deepStrictEqual(BigInt_.fromNumber(Number.MIN_SAFE_INTEGER - 1), Option.none())
+    assert.deepStrictEqual(BigInt_.fromNumber(Infinity), Option.none())
+    assert.deepStrictEqual(BigInt_.fromNumber(-Infinity), Option.none())
+    assert.deepStrictEqual(BigInt_.fromNumber(NaN), Option.none())
+    assert.deepStrictEqual(BigInt_.fromNumber(1e100), Option.none())
+    assert.deepStrictEqual(BigInt_.fromNumber(-1e100), Option.none())
+    assert.deepStrictEqual(BigInt_.fromNumber(3.14), Option.none())
+    assert.deepStrictEqual(BigInt_.fromNumber(-3.14), Option.none())
+    assert.deepStrictEqual(BigInt_.fromNumber(0), Option.some(BigInt(0)))
+    assert.deepStrictEqual(BigInt_.fromNumber(42), Option.some(BigInt(42)))
+    assert.deepStrictEqual(BigInt_.fromNumber(-42), Option.some(BigInt(-42)))
   })
 })