Added order to defaults (Sources, Preprocessors and ParamMappers) (#229)

* Added order to defaults (Sources, Preprocessors and ParamMappers)

* Revert "Added order to defaults (Sources, Preprocessors and ParamMappers)"

This reverts commit 4964b19

* Added order to defaults by, when manually added, adding them where specified

hoplite-core/src/main/kotlin/com/sksamuel/hoplite/ConfigLoader.kt

@@ -118,14 +118,23 @@ class ConfigLoader constructor(
     private var defaultPreprocessors = true
     private var defaultParamMappers = true
 
+    /**
+     * Adds before the specified ones
+     */
     fun withDefaultSources(defaultSources: Boolean): Builder = apply {
       this.defaultSources = defaultSources
     }
 
+    /**
+     * Adds before the specified ones
+     */
     fun withDefaultPreprocessors(defaultPreprocessors: Boolean): Builder = apply {
       this.defaultPreprocessors = defaultPreprocessors
     }
 
+    /**
+     * Adds before the specified ones
+     */
     fun withDefaultParamMappers(defaultParamMappers: Boolean): Builder = apply {
       this.defaultParamMappers = defaultParamMappers
     }
@@ -167,10 +176,22 @@ class ConfigLoader constructor(
 
     fun addSources(sources: Iterable<PropertySource>) = addPropertySources(sources)
 
+    fun addDefaultSources(): Builder {
+      withDefaultSources(false)
+
+      return addPropertySources(defaultPropertySources())
+    }
+
     fun addPropertySources(propertySources: Iterable<PropertySource>): Builder = apply {
       this.propertySourceStaging.addAll(propertySources)
     }
 
+    fun addDefaultPropertySources(): Builder {
+      withDefaultSources(false)
+
+      return addPropertySources(defaultPropertySources())
+    }
+
     fun addPreprocessor(preprocessor: Preprocessor): Builder = apply {
       this.preprocessorStaging.add(preprocessor)
     }
@@ -179,6 +200,12 @@ class ConfigLoader constructor(
       this.preprocessorStaging.addAll(preprocessors)
     }
 
+    fun addDefaultPreprocessors(): Builder {
+      withDefaultPreprocessors(false)
+
+      return addPreprocessors(defaultPreprocessors())
+    }
+
     fun addParameterMapper(paramMapper: ParameterMapper): Builder = apply {
       this.paramMapperStaging.add(paramMapper)
     }
@@ -187,6 +214,12 @@ class ConfigLoader constructor(
       this.paramMapperStaging.addAll(paramMappers)
     }
 
+    fun addDefaultParameterMappers(): Builder {
+      withDefaultParamMappers(false)
+
+      return addParameterMappers(defaultParamMappers())
+    }
+
     /**
      * Registers a callback that will be invoked with any exception generated when
      * the [loadConfigOrThrow] operation is used. The callback will be invoked immediately
@@ -374,7 +407,7 @@ class ConfigLoader constructor(
   private fun loadNode(configs: List<ConfigSource>): ConfigResult<Node> {
     val srcs = propertySources + configs.map { ConfigFilePropertySource(it) }
     return srcs.map { it.node(PropertySourceContext(parserRegistry)) }.sequence()
-      .map { it.takeUnless { it.isEmpty() }?.reduce { acc, b -> acc.merge(b) } ?: NullNode(Pos.NoPos)}
+      .map { it.takeUnless { it.isEmpty() }?.reduce { acc, b -> acc.merge(b) } ?: NullNode(Pos.NoPos) }
       .mapInvalid {
         val multipleFailures = ConfigFailure.MultipleFailures(it)
         multipleFailures

hoplite-core/src/test/kotlin/com/sksamuel/hoplite/PropertySourceTest.kt

@@ -1,6 +1,7 @@
 package com.sksamuel.hoplite
 
 import io.kotest.core.spec.style.FunSpec
+import io.kotest.extensions.system.withEnvironment
 import io.kotest.matchers.shouldBe
 
 class PropertySourceTest : FunSpec() {
@@ -76,5 +77,49 @@ class PropertySourceTest : FunSpec() {
       config shouldBe TestConfig("A value", 42, listOf("Value1", "Value2"))
     }
 
+    test("reads from added source before defaults") {
+      data class TestConfig(val a: String, val b: Int, val other: List<String>)
+
+      withEnvironment(mapOf("b" to "91", "other" to "Random13")) {
+
+        val arguments = arrayOf(
+          "--a=A value",
+          "--b=42",
+          "some other value",
+          "--other=Value1",
+          "--other=Value2",
+        )
+
+        val config = ConfigLoader.Builder()
+          .addPropertySource(PropertySource.commandLine(arguments))
+          .addDefaultPropertySources()
+          .build()
+          .loadConfigOrThrow<TestConfig>()
+
+        config shouldBe TestConfig("A value", 42, listOf("Value1", "Value2"))
+      }
+    }
+
+    test("reads from default source before specified") {
+      data class TestConfig(val a: String, val b: Int, val other: List<String>)
+
+      withEnvironment(mapOf("b" to "91", "other" to "Random13")) {
+        val arguments = arrayOf(
+          "--a=A value",
+          "--b=42",
+          "some other value",
+          "--other=Value1",
+          "--other=Value2",
+        )
+
+        val config = ConfigLoader.Builder()
+          .addDefaultPropertySources()
+          .addPropertySource(PropertySource.commandLine(arguments))
+          .build()
+          .loadConfigOrThrow<TestConfig>()
+
+        config shouldBe TestConfig("A value", 91, listOf("Random13"))
+      }
+    }
   }
 }

hoplite-core/src/test/kotlin/com/sksamuel/hoplite/preprocessor/PropsPreprocessorTest.kt

@@ -2,6 +2,7 @@ package com.sksamuel.hoplite.preprocessor
 
 import com.sksamuel.hoplite.ConfigLoader
 import io.kotest.core.spec.style.StringSpec
+import io.kotest.extensions.system.withEnvironment
 import io.kotest.matchers.shouldBe
 
 class PropsPreprocessorTest : StringSpec() {
@@ -12,11 +13,46 @@ class PropsPreprocessorTest : StringSpec() {
 
       val preprocessor = PropsPreprocessor("/sample.properties")
 
-      val config = ConfigLoader()
-        .withPreprocessor(preprocessor)
+      val config = ConfigLoader.Builder()
+        .addPreprocessor(preprocessor)
+        .build()
         .loadConfigOrThrow<Config>("/processme.props")
 
       config shouldBe Config(a = "I'm on branch master", b = "this replacement doesn't exist \${foo}")
     }
+
+    "should replace props from file, by defaults before specified" {
+      data class Config(val a: String, val b: String)
+
+      withEnvironment(mapOf("git.branch" to "main")) {
+
+        val preprocessor = PropsPreprocessor("/sample.properties")
+
+        val config = ConfigLoader.Builder()
+          .addDefaultPreprocessors()
+          .addPreprocessor(preprocessor)
+          .build()
+          .loadConfigOrThrow<Config>("/processme.props")
+
+        config shouldBe Config(a = "I'm on branch main", b = "this replacement doesn't exist \${foo}")
+      }
+    }
+
+    "should replace props from file, by specified before defaults" {
+      data class Config(val a: String, val b: String)
+
+      withEnvironment(mapOf("git.branch" to "main", "foo" to "nevermind, it does!")) {
+        val preprocessor = PropsPreprocessor("/sample.properties")
+
+        val config = ConfigLoader.Builder()
+          .addPreprocessor(preprocessor)
+          .addDefaultPreprocessors()
+          .build()
+          .loadConfigOrThrow<Config>("/processme.props")
+
+        config shouldBe Config(a = "I'm on branch master",
+          b = "this replacement doesn't exist nevermind, it does!")
+      }
+    }
   }
 }