Adding the support for empty TOML

orchestr7 · Jan 27, 2022 · 2295a74 · 2295a74
1 parent cc6e05a
commit 2295a74
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Showing 5 changed files with 34 additions and 20 deletions.
diff --git a/README.md b/README.md
@@ -25,7 +25,8 @@ In case you don't have much time for this - at least spend 5 seconds to give us
 **Thanks!** :pray:
 
 ### Acknowledgement
-Special thanks to those devoted who help us maintain and improve the project: @NightEule5, @Peanuuutz, @petertrr, @Olivki and @edrd-f.
+Special thanks to those awesome developers who give us great suggestions, help us to maintain and improve this project:
+@NightEule5, @Peanuuutz, @petertrr, @Olivki and @edrd-f.
 
 ## Supported platforms
 All the code is written in Kotlin **common** module. This means that it can be built for each and every Kotlin native platform.
@@ -192,7 +193,11 @@ Toml(
         // allow/prohibit empty values like "a = # comment", default true
         emptyValuesAllowed = true,
         // allow/prohibit escaping of single quotes in literal strings, default true
-        escapedQuotesInLiteralStringsAllowed = true
+        escapedQuotesInLiteralStringsAllowed = true,
+        // allow/prohibit processing of empty toml, if false - throws an InternalDecodingException exception, default is true
+        allowEmptyToml = true,
+        // indentation symbols for serialization, default 4 spaces
+        indentation = Indentation.FOUR_SPACES,
     )
 ).decodeFromString<MyClass>(
     tomlString

diff --git a/ktoml-core/src/commonMain/kotlin/com/akuleshov7/ktoml/TomlConfig.kt b/ktoml-core/src/commonMain/kotlin/com/akuleshov7/ktoml/TomlConfig.kt
@@ -20,16 +20,18 @@ public class KtomlConf(
  * @property ignoreUnknownNames - a control to allow/prohibit unknown names during the deserialization
  * @property allowEmptyValues - a control to allow/prohibit empty values: a = # comment
  * @property allowEscapedQuotesInLiteralStrings - a control to allow/prohibit escaping of single quotes in literal strings
- * @property indentation
+ * @property indentation - the number of spaces in the indents for the serialization
+ * @property allowEmptyToml - controls if empty toml can be processed, if false - will throw an exception
  */
 public open class TomlConfig(
     public val ignoreUnknownNames: Boolean = false,
     public val allowEmptyValues: Boolean = true,
     public val allowEscapedQuotesInLiteralStrings: Boolean = true,
     public val indentation: Indentation = Indentation.FOUR_SPACES,
+    public val allowEmptyToml: Boolean = true,
 ) {
     /**
-     * @property value
+     * @property value - string with indents, used for the formatting of serialization
      */
     public enum class Indentation(public val value: String) {
         FOUR_SPACES("    "),

diff --git a/ktoml-core/src/commonMain/kotlin/com/akuleshov7/ktoml/decoders/TomlMainDecoder.kt b/ktoml-core/src/commonMain/kotlin/com/akuleshov7/ktoml/decoders/TomlMainDecoder.kt
@@ -51,7 +51,8 @@ public class TomlMainDecoder(
     }
 
     // the iteration will go through all elements that will be found in the input
-    private fun isDecodingDone() = elementIndex == rootNode.getNeighbourNodes().size
+    private fun isDecodingDone() =
+            if (rootNode is TomlFile) true else elementIndex == rootNode.getNeighbourNodes().size
 
     /**
      * Getting the node with the value
@@ -177,10 +178,15 @@ public class TomlMainDecoder(
     override fun beginStructure(descriptor: SerialDescriptor): CompositeDecoder = when (rootNode) {
         is TomlFile -> {
             checkMissingRequiredProperties(rootNode.children, descriptor)
-            val firstFileChild = rootNode.getFirstChild() ?: throw InternalDecodingException(
-                "Missing child nodes (tables, key-values) for TomlFile." +
-                        " Was empty toml provided to the input?"
-            )
+            val firstFileChild = rootNode.getFirstChild() ?: if (!config.allowEmptyToml) {
+                throw InternalDecodingException(
+                    "Missing child nodes (tables, key-values) for TomlFile." +
+                            " Was empty toml provided to the input?"
+                )
+            } else {
+                rootNode
+            }
+
             TomlMainDecoder(firstFileChild, config)
         }
         else -> {

diff --git a/ktoml-core/src/commonMain/kotlin/com/akuleshov7/ktoml/tree/TomlNode.kt b/ktoml-core/src/commonMain/kotlin/com/akuleshov7/ktoml/tree/TomlNode.kt
@@ -23,7 +23,8 @@ import com.akuleshov7.ktoml.parsers.trimQuotes
 public sealed class TomlNode(
     public open val content: String,
     public open val lineNo: Int,
-    public open val config: TomlConfig = TomlConfig()) {
+    public open val config: TomlConfig = TomlConfig()
+) {
     public open val children: MutableSet<TomlNode> = mutableSetOf()
     public open var parent: TomlNode? = null
 

diff --git a/ktoml-core/src/commonTest/kotlin/com/akulashov7/ktoml/decoders/NullableTablesTest.kt b/ktoml-core/src/commonTest/kotlin/com/akulashov7/ktoml/decoders/NullableTablesTest.kt
@@ -82,19 +82,19 @@ class NullableTablesTest {
 class EmptyTomlTest {
     @Test
     fun emptyToml() {
-        assertFailsWith<InternalDecodingException> {
-            Toml().decodeFromString<Config>(
-                """            
+        var res = Toml().decodeFromString<Config>(
+            """            
              
              
                 """.trimIndent()
-            )
-        }
+        )
 
-        assertFailsWith<InternalDecodingException> {
-            Toml().decodeFromString(
-                "".trimIndent()
-            )
-        }
+        assertEquals(Config(), res)
+
+        res = Toml().decodeFromString<Config>(
+            "".trimIndent()
+        )
+
+        assertEquals(Config(), res)
     }
 }