Parser: new VaultPreprocessing component for performing compatibility…

… adjustments and other last-minute changes over uncontrolled inputs, right before compilation happens

README.md

@@ -19,7 +19,7 @@ Add the following in your `pom.xml`:
 <dependency>
     <groupId>com.lumiomedical</groupId>
     <artifactId>lumio-vault</artifactId>
-    <version>0.9.1</version>
+    <version>0.10</version>
 </dependency>
 ```
 
@@ -93,6 +93,7 @@ Other features that will need to be documented include:
 * service closing
 * service container composition
 * custom modules
+* custom preprocessing routines
 
 _TODO_
 

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>com.lumiomedical</groupId>
     <artifactId>lumio-vault</artifactId>
-    <version>0.9.1</version>
+    <version>0.10</version>
     <packaging>jar</packaging>
 
     <name>Lumio Vault</name>

src/main/java/com/lumiomedical/vault/parser/VaultCompositeParser.java

@@ -7,6 +7,7 @@
 import com.lumiomedical.vault.exception.VaultStructureException;
 import com.lumiomedical.vault.parser.adjuster.VaultAdjuster;
 import com.lumiomedical.vault.parser.module.*;
+import com.lumiomedical.vault.parser.preprocessor.VaultPreprocessor;
 import com.lumiomedical.vault.parser.resolver.FlexibleResolver;
 import com.lumiomedical.vault.parser.resolver.VaultResolver;
 import com.lumiomedical.vault.parser.resolver.source.Source;
@@ -27,6 +28,7 @@ public class VaultCompositeParser implements VaultParser
     private final VaultResolver resolver;
     private static final String rootIdentifier = "*";
     private static final Set<String> coreDirectives = Set.of("imports");
+    private final List<VaultPreprocessor> preprocessors = new ArrayList<>();
     /* Module stacks */
     private final List<VaultModule> preModules = Lists.of(
         new VariableRegistrationModule()
@@ -110,6 +112,11 @@ private ObjectNode compileNode(Source source, ObjectNode rootNode) throws VaultP
     {
         try {
             ObjectNode json = source.interpret();
+
+            /* The preprocessor pass can be used to perform compatibility adjustments or last-minute changes over uncontrolled inputs */
+            for (VaultPreprocessor preprocessor : this.preprocessors)
+                json = preprocessor.preprocess(json);
+
             this.validateStructure(json);
 
             for (String imp : this.getImports(json))
@@ -156,6 +163,12 @@ private ObjectNode compileNode(Source source, ObjectNode rootNode) throws VaultP
         }
     }
 
+    @Override
+    public VaultParser registerPreprocessor(VaultPreprocessor preprocessor)
+    {
+        this.preprocessors.add(preprocessor);
+        return this;
+    }
 
     @Override
     public VaultParser register(VaultModule module)

src/main/java/com/lumiomedical/vault/parser/VaultParser.java

@@ -4,6 +4,7 @@
 import com.lumiomedical.vault.exception.VaultParserException;
 import com.lumiomedical.vault.parser.adjuster.VaultAdjuster;
 import com.lumiomedical.vault.parser.module.VaultModule;
+import com.lumiomedical.vault.parser.preprocessor.VaultPreprocessor;
 import com.lumiomedical.vault.parser.resolver.source.Source;
 
 import java.util.Arrays;
@@ -81,8 +82,17 @@ default Definitions extractOrigin(Collection<String> origins, Definitions defini
     Definitions extractOrigin(Collection<String> origins, Definitions definitions, Collection<VaultAdjuster> adjusters) throws VaultParserException;
 
     /**
+     * Register a custom preprocessor for performing modifications over configuration nodes before compilation passes.
      *
-     * @param module
+     * @param preprocessor a vault preprocessor instance
+     * @return
+     */
+    VaultParser registerPreprocessor(VaultPreprocessor preprocessor);
+
+    /**
+     * Register a custom module for performing additional processing over configuration nodes.
+     *
+     * @param module a vault module instance
      * @return
      */
     VaultParser register(VaultModule module);

src/main/java/com/lumiomedical/vault/parser/preprocessor/VaultPreprocessor.java

@@ -0,0 +1,23 @@
+package com.lumiomedical.vault.parser.preprocessor;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.lumiomedical.vault.exception.VaultParserException;
+
+/**
+ * The preprocessors are expected to be used to perform compatibility adjustments or last-minute changes over uncontrolled inputs.
+ * Preprocessing should happen before structure validation and before compilation.
+ *
+ * @author Pierre Lecerf (plecerf@lumiomedical.com)
+ * Created on 2021/01/25
+ */
+public interface VaultPreprocessor
+{
+    /**
+     * Can alter a given configuration node, or leave it as is, before it goes through compilation.
+     *
+     * @param node A configuration node
+     * @return an altered configuration node
+     * @throws VaultParserException
+     */
+    ObjectNode preprocess(ObjectNode node) throws VaultParserException;
+}

src/test/java/com/lumiomedical/vault/parser/ParserTest.java

@@ -31,7 +31,7 @@ void basicYamlParsing() throws VaultParserException
         makeAssertions(def);
     }
 
-    void makeAssertions(Definitions def)
+    public static void makeAssertions(Definitions def)
     {
         Assertions.assertEquals(true, def.getVariable("provider.boolean.value"));
         Assertions.assertEquals(12.34, def.getVariable("provider.double.value"));

src/test/java/com/lumiomedical/vault/parser/PreprocessorTest.java

@@ -0,0 +1,64 @@
+package com.lumiomedical.vault.parser;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.lumiomedical.vault.container.definition.Definitions;
+import com.lumiomedical.vault.exception.VaultParserException;
+import com.noleme.json.Json;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import static com.noleme.commons.function.RethrowConsumer.rethrower;
+
+/**
+ * @author Pierre Lecerf (plecerf@lumiomedical.com)
+ * Created on 2020/11/24
+ */
+public class PreprocessorTest
+{
+    @Test
+    void test() throws VaultParserException
+    {
+        var parser = new VaultCompositeParser();
+
+        Assertions.assertThrows(VaultParserException.class, () -> {
+            parser.extract("com/lumiomedical/vault/parser/simple.old_style.json");
+        });
+
+        parser.registerPreprocessor(PreprocessorTest::preprocessor);
+
+        Assertions.assertDoesNotThrow(() -> parser.extract("com/lumiomedical/vault/parser/simple.old_style.json"));
+
+        Definitions definitions = parser.extract("com/lumiomedical/vault/parser/simple.old_style.json");
+
+        ParserTest.makeAssertions(definitions);
+    }
+
+    /**
+     *
+     * @param node
+     * @return
+     * @throws VaultParserException
+     */
+    private static ObjectNode preprocessor(ObjectNode node) throws VaultParserException
+    {
+        if (!node.has("services") || !node.get("services").isArray())
+            return node;
+
+        var objServices = Json.newObject();
+
+        node.get("services").forEach(rethrower(serviceNode -> {
+
+            if (!serviceNode.has("identifier"))
+                throw new VaultParserException("A service node declared in an old-style service array has no identifier field.");
+
+            objServices.set(
+                serviceNode.get("identifier").asText(),
+                serviceNode
+            );
+        }));
+
+        node.set("services", objServices);
+
+        return node;
+    }
+}

src/test/resources/com/lumiomedical/vault/parser/provider.integer.old_style.json

@@ -0,0 +1,14 @@
+{
+    "variables": {
+        "provider.integer.value": 1234
+    },
+    "services": [
+        {
+            "identifier": "provider.integer",
+            "class": "com.lumiomedical.vault.service.IntegerProvider",
+            "constructor": [
+                "##provider.integer.value##"
+            ]
+        }
+    ]
+}

src/test/resources/com/lumiomedical/vault/parser/simple.old_style.json

@@ -0,0 +1,49 @@
+{
+    "imports": [
+        "com/lumiomedical/vault/parser/provider.string.json",
+        "com/lumiomedical/vault/parser/provider.boolean.json",
+        "com/lumiomedical/vault/parser/provider.integer.old_style.json"
+    ],
+    "variables": {
+        "provider.integer.value": 2345,
+        "provider.double.value": 12.34,
+        "provider.string.base_value": "SomeString",
+        "provider.string.value": "##provider.string.base_value##"
+    },
+    "services": [
+        {
+            "identifier": "alias.string",
+            "alias": "provider.string"
+        },
+        {
+            "identifier": "provider.boolean.base",
+            "class": "com.lumiomedical.vault.service.BooleanProvider",
+            "constructor": [ false ]
+        },
+        {
+            "identifier": "provider.double",
+            "class": "com.lumiomedical.vault.service.DoubleProvider",
+            "constructor": [
+                "##provider.double.value##"
+            ],
+            "invocations": [
+                ["provide"]
+            ]
+        },
+        {
+            "identifier": "provider.string",
+            "class": "com.lumiomedical.vault.service.StringProvider",
+            "method": "build",
+            "arguments": [
+                "##provider.string.value##"
+            ]
+        },
+        {
+            "identifier": "provider.boolean",
+            "class": "com.lumiomedical.vault.service.ServiceProvider",
+            "arguments": [
+                "@provider.boolean.base"
+            ]
+        }
+    ]
+}