test: migrate PriceTest to Kotlin. (#728)

Author: overcat

src/test/java/org/stellar/sdk/PriceTest.java

@@ -0,0 +1,67 @@
+package org.stellar.sdk
+
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.datatest.withData
+import io.kotest.matchers.shouldBe
+
+data class PriceTestCase(
+  val input: String,
+  val expectedNumerator: Int,
+  val expectedDenominator: Int,
+)
+
+class PriceTest :
+  FunSpec({
+    context("Price.fromString()") {
+      withData(
+        nameFn = {
+          "should parse '${it.input}' to ${it.expectedNumerator}/${it.expectedDenominator}"
+        },
+        PriceTestCase("0", 0, 1),
+        PriceTestCase("0.1", 1, 10),
+        PriceTestCase("0.01", 1, 100),
+        PriceTestCase("0.001", 1, 1000),
+        PriceTestCase("543.01793", 54301793, 100000),
+        PriceTestCase("319.69983", 31969983, 100000),
+        PriceTestCase("0.93", 93, 100),
+        PriceTestCase("0.5", 1, 2),
+        PriceTestCase("1.730", 173, 100),
+        PriceTestCase("0.85334384", 5333399, 6250000),
+        PriceTestCase("5.5", 11, 2),
+        PriceTestCase("2.72783", 272783, 100000),
+        PriceTestCase("638082.0", 638082, 1),
+        PriceTestCase("2.93850088", 36731261, 12500000),
+        PriceTestCase("58.04", 1451, 25),
+        PriceTestCase("41.265", 8253, 200),
+        PriceTestCase("5.1476", 12869, 2500),
+        PriceTestCase("95.14", 4757, 50),
+        PriceTestCase("0.74580", 3729, 5000),
+        PriceTestCase("4119.0", 4119, 1),
+        PriceTestCase("1073742464.5", 1073742464, 1),
+        PriceTestCase("1635962526.2", 1635962526, 1),
+        PriceTestCase("2147483647", 2147483647, 1),
+      ) { testCase ->
+        val price = Price.fromString(testCase.input)
+        price.numerator shouldBe testCase.expectedNumerator
+        price.denominator shouldBe testCase.expectedDenominator
+        Price.fromXdr(price.toXdr()) shouldBe price
+      }
+    }
+
+    context("Price constructor") {
+      test("should create price with numerator and denominator") {
+        val price = Price(3, 4)
+        price.numerator shouldBe 3
+        price.denominator shouldBe 4
+      }
+    }
+
+    context("Price.toString()") {
+      test("should return decimal representation") {
+        Price(1, 2).toString() shouldBe "0.5"
+        Price(3, 4).toString() shouldBe "0.75"
+        Price(5, 1).toString() shouldBe "5"
+        Price(0, 1).toString() shouldBe "0"
+      }
+    }
+  })