fix(abg): properly handle types manifest with only comments (#1793)

Author: Vampire

action-binding-generator/src/main/kotlin/io/github/typesafegithub/workflows/actionbindinggenerator/typing/TypesProviding.kt

@@ -1,6 +1,7 @@
 package io.github.typesafegithub.workflows.actionbindinggenerator.typing
 
 import com.charleskorn.kaml.AnchorsAndAliases
+import com.charleskorn.kaml.EmptyYamlDocumentException
 import com.charleskorn.kaml.Yaml
 import io.github.oshai.kotlinlogging.KotlinLogging.logger
 import io.github.typesafegithub.workflows.actionbindinggenerator.domain.ActionCoords
@@ -150,7 +151,14 @@ private inline fun <reified T> Yaml.decodeFromStringOrDefaultIfEmpty(
     default: T,
 ): T =
     if (text.isNotBlank()) {
-        decodeFromString(text)
+        runCatching {
+            decodeFromString<T>(text)
+        }.getOrElse {
+            if (it is EmptyYamlDocumentException) {
+                return default
+            }
+            throw it
+        }
     } else {
         default
     }

action-binding-generator/src/test/kotlin/io/github/typesafegithub/workflows/actionbindinggenerator/typing/TypesProvidingTest.kt

@@ -12,6 +12,30 @@ import java.net.URI
 
 class TypesProvidingTest :
     FunSpec({
+        test("copes with blank typing") {
+            // Given
+            val actionTypesYml = " "
+            val actionCoord = ActionCoords("some-owner", "some-name", "v1")
+
+            // When
+            val types = actionCoord.provideTypes(metadataRevision = CommitHash("some-hash"), { actionTypesYml })
+
+            // Then
+            types.first shouldBe emptyMap()
+        }
+
+        test("copes with comment-only typing") {
+            // Given
+            val actionTypesYml = "#"
+            val actionCoord = ActionCoords("some-owner", "some-name", "v1")
+
+            // When
+            val types = actionCoord.provideTypes(metadataRevision = CommitHash("some-hash"), { actionTypesYml })
+
+            // Then
+            types.first shouldBe emptyMap()
+        }
+
         test("parses all allowed elements of valid typing") {
             // Given
             val actionTypesYml =