Remove deprecated functions from api.ts (aka client.ts) (#1534)

* Removed deprecated functions from client.ts

* Renamed files to be camelCase

* Created top-level utils folder and tied all sub-references to it

* Grouped tests for those utils into their own section

Co-authored-by: Nathan Nichols <natenichols@cox.net>

test/utils/xrpToDrops.ts

@@ -0,0 +1,108 @@
+import assert from 'assert-diff'
+import BigNumber from 'bignumber.js'
+import {xrpToDrops} from '../../src/utils'
+
+describe('XRP To Drops', function () {
+  it('works with a typical amount', () => {
+    const drops = xrpToDrops('2')
+    assert.strictEqual(drops, '2000000', '2 XRP equals 2 million drops')
+  })
+
+  it('works with fractions', () => {
+    let drops = xrpToDrops('3.456789')
+    assert.strictEqual(drops, '3456789', '3.456789 XRP equals 3,456,789 drops')
+    drops = xrpToDrops('3.400000')
+    assert.strictEqual(drops, '3400000', '3.400000 XRP equals 3,400,000 drops')
+    drops = xrpToDrops('0.000001')
+    assert.strictEqual(drops, '1', '0.000001 XRP equals 1 drop')
+    drops = xrpToDrops('0.0000010')
+    assert.strictEqual(drops, '1', '0.0000010 XRP equals 1 drop')
+  })
+
+  it('works with zero', () => {
+    let drops = xrpToDrops('0')
+    assert.strictEqual(drops, '0', '0 XRP equals 0 drops')
+    drops = xrpToDrops('-0') // negative zero is equivalent to zero
+    assert.strictEqual(drops, '0', '-0 XRP equals 0 drops')
+    drops = xrpToDrops('0.000000')
+    assert.strictEqual(drops, '0', '0.000000 XRP equals 0 drops')
+    drops = xrpToDrops('0.0000000')
+    assert.strictEqual(drops, '0', '0.0000000 XRP equals 0 drops')
+  })
+
+  it('works with a negative value', () => {
+    const drops = xrpToDrops('-2')
+    assert.strictEqual(drops, '-2000000', '-2 XRP equals -2 million drops')
+  })
+
+  it('works with a value ending with a decimal point', () => {
+    let drops = xrpToDrops('2.')
+    assert.strictEqual(drops, '2000000', '2. XRP equals 2000000 drops')
+    drops = xrpToDrops('-2.')
+    assert.strictEqual(drops, '-2000000', '-2. XRP equals -2000000 drops')
+  })
+
+  it('works with BigNumber objects', () => {
+    let drops = xrpToDrops(new BigNumber(2))
+    assert.strictEqual(
+      drops,
+      '2000000',
+      '(BigNumber) 2 XRP equals 2 million drops'
+    )
+    drops = xrpToDrops(new BigNumber(-2))
+    assert.strictEqual(
+      drops,
+      '-2000000',
+      '(BigNumber) -2 XRP equals -2 million drops'
+    )
+  })
+
+  it('works with a number', () => {
+    // This is not recommended. Use strings or BigNumber objects to avoid precision errors.
+    let drops = xrpToDrops(2)
+    assert.strictEqual(
+      drops,
+      '2000000',
+      '(number) 2 XRP equals 2 million drops'
+    )
+    drops = xrpToDrops(-2)
+    assert.strictEqual(
+      drops,
+      '-2000000',
+      '(number) -2 XRP equals -2 million drops'
+    )
+  })
+
+  it('throws with an amount with too many decimal places', () => {
+    assert.throws(() => {
+      xrpToDrops('1.1234567')
+    }, /has too many decimal places/)
+    assert.throws(() => {
+      xrpToDrops('0.0000001')
+    }, /has too many decimal places/)
+  })
+
+  it('throws with an invalid value', () => {
+    assert.throws(() => {
+      xrpToDrops('FOO')
+    }, /invalid value/)
+    assert.throws(() => {
+      xrpToDrops('1e-7')
+    }, /invalid value/)
+    assert.throws(() => {
+      xrpToDrops('2,0')
+    }, /invalid value/)
+    assert.throws(() => {
+      xrpToDrops('.')
+    }, /xrpToDrops: invalid value '\.', should be a BigNumber or string-encoded number\./)
+  })
+
+  it('throws with an amount more than one decimal point', () => {
+    assert.throws(() => {
+      xrpToDrops('1.0.0')
+    }, /xrpToDrops: invalid value '1\.0\.0'/)
+    assert.throws(() => {
+      xrpToDrops('...')
+    }, /xrpToDrops: invalid value '\.\.\.'/)
+  })
+})