Correct work with empty path segment in JSON pointer

Author: OptimumCode

src/commonMain/kotlin/io/github/optimumcode/json/pointer/JsonPointer.kt

@@ -33,9 +33,7 @@ public sealed class JsonPointer(
  buildString {
  val pointer = this@JsonPointer.toString()
  append(pointer)
- if (!pointer.endsWith(SEPARATOR)) {
- append(SEPARATOR)
- }
+ append(SEPARATOR)
  append(index)
  },
  )
@@ -53,9 +51,7 @@ public sealed class JsonPointer(
  buildString {
  val pointer = this@JsonPointer.toString()
  append(pointer)
- if (!pointer.endsWith(SEPARATOR)) {
- append(SEPARATOR)
- }
+ append(SEPARATOR)
  append(property)
  },
  )

src/commonMain/kotlin/io/github/optimumcode/json/pointer/extensions.kt

@@ -57,13 +57,8 @@ public operator fun JsonPointer.plus(otherPointer: JsonPointer): JsonPointer {
  }
  return JsonPointer(
  buildString {
- val pointer = this@plus.toString()
- append(pointer)
- if (pointer.endsWith(JsonPointer.SEPARATOR)) {
- setLength(length - 1)
- }
- val other = otherPointer.toString()
- append(other)
+ append(this@plus.toString())
+ append(otherPointer.toString())
  },
  )
 }

src/commonTest/kotlin/io/github/optimumcode/json/pointer/JsonPointerExtensionsTest.kt

@@ -18,11 +18,21 @@ class JsonPointerExtensionsTest : FunSpec() {
  "prop",
  JsonPointer("/prop"),
  ),
+ TestCase(
+ JsonPointer.ROOT,
+ "",
+ JsonPointer("/"),
+ ),
  TestCase(
  JsonPointer("/test"),
  "prop",
  JsonPointer("/test/prop"),
  ),
+ TestCase(
+ JsonPointer("/test"),
+ "",
+ JsonPointer("/test/"),
+ ),
  ).forEach { (initial, prop, result) ->
  test("$initial / $prop => $result") {
  (initial / prop) shouldBe result
@@ -40,6 +50,11 @@ class JsonPointerExtensionsTest : FunSpec() {
  0,
  JsonPointer("/test/0"),
  ),
+ TestCase(
+ JsonPointer("/test/"),
+ 0,
+ JsonPointer("/test//0"),
+ ),
  ).forEach { (initial, prop, result) ->
  test("$initial [ $prop ] => $result") {
  (initial[prop]) shouldBe result
@@ -67,6 +82,11 @@ class JsonPointerExtensionsTest : FunSpec() {
  JsonPointer("/test2"),
  JsonPointer("/test1/test2"),
  ),
+ TestCase(
+ JsonPointer("/test1/"),
+ JsonPointer("/test2"),
+ JsonPointer("/test1//test2"),
+ ),
  ).forEach { (init, append, result) ->
  test("$init + $append => $result") {
  (init + append) shouldBe result
@@ -89,6 +109,11 @@ class JsonPointerExtensionsTest : FunSpec() {
  JsonPointer("/test/data"),
  JsonPointer("/data"),
  ),
+ TestCase(
+ JsonPointer("/test"),
+ JsonPointer("/test//data"),
+ JsonPointer("//data")
+ )
  ).forEach { (base, relativeToBase, relativePath) ->
  test("relative path from '$base' to '$relativeToBase' is '$relativePath'") {
  base.relative(relativeToBase) shouldBe relativePath

src/commonTest/kotlin/io/github/optimumcode/json/pointer/JsonPointerTest.kt

@@ -4,6 +4,7 @@ import io.kotest.assertions.asClue
 import io.kotest.assertions.assertSoftly
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.nulls.shouldNotBeNull
 import io.kotest.matchers.should
 import io.kotest.matchers.shouldBe
 import io.kotest.matchers.shouldNotBe
@@ -77,6 +78,38 @@ class JsonPointerTest : FunSpec() {
  val pointer = JsonPointer("/~")
  pointer.assertSegment(property = "~")
  }
+
+ test("empty segment in the end") {
+ val pointer = JsonPointer("/test/")
+ assertSoftly {
+ pointer.assertSegment(property = "test")
+ pointer.next
+ .shouldNotBeNull()
+ .assertSegment(property = "")
+ pointer.toString() shouldBe "/test/"
+ }
+ }
+
+ test("empty segment in the beginning") {
+ val pointer = JsonPointer("/")
+ assertSoftly {
+ pointer.assertSegment(property = "")
+ pointer.next.shouldNotBeNull().shouldBe(EmptyPointer)
+ pointer.toString() shouldBe "/"
+ }
+ }
+
+ test("empty segment in the middle") {
+ val pointer = JsonPointer("/test1//test2")
+ assertSoftly {
+ pointer.assertSegment(property = "test1")
+ var next = pointer.next.shouldNotBeNull()
+ next.assertSegment(property = "")
+ next = next.next.shouldNotBeNull()
+ next.assertSegment(property = "test2")
+ pointer.toString() shouldBe "/test1//test2"
+ }
+ }
  }
 
  private fun JsonPointer.assertSegment(property: String, index: Int = -1) {