Merge pull request #84 from gestalt-config/feat/substitutionDefaults

You can provide a default for the substitution
gestalt-config · Apr 26, 2023 · 7fd89ec · 7fd89ec
2 parents 3890ede + acc0c40
commit 7fd89ec
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diff --git a/README.md b/README.md
@@ -370,7 +370,14 @@ You can specify the substitution in the format ${transform:key} or ${key}. If yo
 Unlike the rest of Gestalt, this is case-sensitive, and it does not tokenize the string (except the node transform). The key expects an exact match, so if the Environment Variable name is DB_USER you need to use the key DB_USER, db.user or db_user will not match.
 
 ```properties
-db.uri=jdbc:mysql://${env:DB_HOST}:${map:DB_PORT}/${sys:environment}
+db.uri=jdbc:mysql://${DB_HOST}:${map:DB_PORT}/${sys:environment}
+```
+
+### Defaults for a Substitution
+You can provide a default for the substitution in the format ${transform:key:=default} or ${key:=default}. If you provide a default it will use the default value in the event that the key provided cant be found
+
+```properties
+db.uri=jdbc:mysql://${DB_HOST}:${map:DB_PORT:=3306}/${environment:=dev}
 ```
 
 ### Escaping a Substitution

diff --git a/build.gradle.kts b/build.gradle.kts
@@ -8,7 +8,7 @@ plugins {
 
 allprojects {
     group = "com.github.gestalt-config"
-    version = "0.20.4"
+    version = "0.20.5"
 }
 
 
diff --git a/gestalt-core/src/main/java/org/github/gestalt/config/builder/GestaltBuilder.java b/gestalt-core/src/main/java/org/github/gestalt/config/builder/GestaltBuilder.java
@@ -84,6 +84,10 @@ public class GestaltBuilder {
     // the maximum nested substitution depth.
     private Integer maxSubstitutionNestedDepth = null;
 
+    // the regex used to parse string substitutions.
+    // Must have a named capture group transform, key, and default, where the key is required and the transform and default are optional.
+    private String substitutionRegex = null;
+
     /**
      * Adds all default decoders to the builder. Uses the ServiceLoader to find all registered Decoders and adds them
      *
@@ -613,6 +617,26 @@ public void setMaxSubstitutionNestedDepth(Integer maxSubstitutionNestedDepth) {
         this.maxSubstitutionNestedDepth = maxSubstitutionNestedDepth;
     }
 
+    /**
+     * the regex used to parse string substitutions.
+     * Must have a named capture group transform, key, and default, where the key is required and the transform and default are optional.
+     *
+     * @return the string substitution regex
+     */
+    public String getSubstitutionRegex() {
+        return substitutionRegex;
+    }
+
+    /**
+     * the regex used to parse string substitutions.
+     * Must have a named capture group transform, key, and default, where the key is required and the transform and default are optional.
+     *
+     * @param substitutionRegex the string substitution regex
+     */
+    public void setSubstitutionRegex(String substitutionRegex) {
+        this.substitutionRegex = substitutionRegex;
+    }
+
 
     /**
      * dedupe decoders and return the deduped list.
@@ -767,6 +791,9 @@ private GestaltConfig rebuildConfig() {
         newConfig.setMaxSubstitutionNestedDepth(Objects.requireNonNullElseGet(maxSubstitutionNestedDepth,
             () -> gestaltConfig.getMaxSubstitutionNestedDepth()));
 
+        newConfig.setSubstitutionRegex(Objects.requireNonNullElseGet(substitutionRegex,
+            () -> gestaltConfig.getSubstitutionRegex()));
+
         return newConfig;
     }
 }
diff --git a/gestalt-core/src/main/java/org/github/gestalt/config/entity/GestaltConfig.java b/gestalt-core/src/main/java/org/github/gestalt/config/entity/GestaltConfig.java
@@ -1,5 +1,7 @@
 package org.github.gestalt.config.entity;
 
+import org.github.gestalt.config.post.process.transform.TransformerPostProcessor;
+
 import java.time.format.DateTimeFormatter;
 
 /**
@@ -35,6 +37,10 @@ public class GestaltConfig {
     // the maximum nested substitution depth.
     private int maxSubstitutionNestedDepth = 5;
 
+    // the regex used to parse string substitutions.
+    // Must have a named capture group transform, key, and default, where the key is required and the transform and default are optional.
+    private String substitutionRegex = TransformerPostProcessor.defaultSubstitutionRegex;
+
     /**
      * Treat all warnings as errors.
      *
@@ -216,4 +222,25 @@ public int getMaxSubstitutionNestedDepth() {
     public void setMaxSubstitutionNestedDepth(int maxSubstitutionNestedDepth) {
         this.maxSubstitutionNestedDepth = maxSubstitutionNestedDepth;
     }
+
+
+    /**
+     * the regex used to parse string substitutions.
+     * Must have a named capture group transform, key, and default, where the key is required and the transform and default are optional.
+     *
+     * @return the string substitution regex
+     */
+    public String getSubstitutionRegex() {
+        return substitutionRegex;
+    }
+
+    /**
+     * the regex used to parse string substitutions.
+     * Must have a named capture group transform, key, and default, where the key is required and the transform and default are optional.
+     *
+     * @param substitutionRegex the string substitution regex
+     */
+    public void setSubstitutionRegex(String substitutionRegex) {
+        this.substitutionRegex = substitutionRegex;
+    }
 }
diff --git a/gestalt-core/src/main/java/org/github/gestalt/config/entity/ValidationError.java b/gestalt-core/src/main/java/org/github/gestalt/config/entity/ValidationError.java
@@ -1115,6 +1115,25 @@ public String description() {
         }
     }
 
+    /**
+     * Transform doesnt match the regex
+     */
+    public static class TransformDoesntMatchRegex extends ValidationError {
+        private final String path;
+        private final String value;
+
+        public TransformDoesntMatchRegex(String path, String value) {
+            super(ValidationLevel.ERROR);
+            this.path = path;
+            this.value = value;
+        }
+
+        @Override
+        public String description() {
+            return "Transform doesnt match the expected format with value " + value + " on path " + path;
+        }
+    }
+
     /**
      * Not a valid SubstitutionNode
      */

diff --git a/.../main/java/org/github/gestalt/config/post/process/transform/TransformerPostProcessor.java b/.../main/java/org/github/gestalt/config/post/process/transform/TransformerPostProcessor.java
@@ -32,9 +32,10 @@
  * @author <a href="mailto:colin.redmond@outlook.com"> Colin Redmond </a> (c) 2023.
  */
 public class TransformerPostProcessor implements PostProcessor {
-    private static final Pattern pattern = Pattern.compile(
-        "((?<transform>\\w+):)?(?<key>[\\w ,_.+;:\"'`~!@#$%^&*()\\[\\]<>]+)"
-    );
+
+    public static final String defaultSubstitutionRegex =
+        "^((?<transform>\\w+):)?(?<key>[\\w ,_.+;\"'`~!@#$%^&*()\\[\\]<>]+)(:=(?<default>[\\w ,_.+;:\"'`~!@#$%^&*()\\[\\]<>]+))?$";
+    private Pattern pattern;
 
     private final Map<String, Transformer> transformers;
     private final List<Transformer> orderedDefaultTransformers;
@@ -55,6 +56,7 @@ public TransformerPostProcessor() {
         });
 
         this.orderedDefaultTransformers = buildOrderedConfigPriorities(transformersList, false);
+        this.pattern = Pattern.compile(defaultSubstitutionRegex);
     }
 
     /**
@@ -70,7 +72,9 @@ public TransformerPostProcessor(List<Transformer> transformers) {
             this.transformers = transformers.stream().collect(Collectors.toMap(Transformer::name, Function.identity()));
             this.orderedDefaultTransformers = buildOrderedConfigPriorities(transformers, false);
         }
+
         this.substitutionTreeBuilder = new SubstitutionTreeBuilder("${", "}");
+        this.pattern = Pattern.compile(defaultSubstitutionRegex);
     }
 
     @Override
@@ -81,6 +85,7 @@ public void applyConfig(PostProcessorConfig config) {
             config.getConfig().getSubstitutionClosingToken());
 
         this.maxRecursionDepth = config.getConfig().getMaxSubstitutionNestedDepth();
+        this.pattern = Pattern.compile(defaultSubstitutionRegex);
     }
 
     @Override
@@ -149,9 +154,11 @@ private ValidateOf<String> transformString(String path, String input) {
         Matcher matcher = pattern.matcher(input);
         StringBuilder newLeafValue = new StringBuilder();
         boolean foundMatch = false;
+
         while (matcher.find()) {
             String transformName = matcher.group("transform");
             String key = matcher.group("key");
+            String defaultValue = matcher.group("default");
 
             // if we have a named transform look it up in the map.
             if (transformName != null) {
@@ -161,7 +168,13 @@ private ValidateOf<String> transformString(String path, String input) {
                         newLeafValue.append(transformValue.results());
                         foundMatch = true;
                     } else {
-                        return ValidateOf.inValid(new ValidationError.NoKeyFoundForTransform(path, transformName, key));
+                        // if we have no results from the transform but a default value, use the default
+                        if (defaultValue != null) {
+                            foundMatch = true;
+                            newLeafValue.append(defaultValue);
+                        } else {
+                            return ValidateOf.inValid(new ValidationError.NoKeyFoundForTransform(path, transformName, key));
+                        }
                     }
                 } else {
                     return ValidateOf.inValid(new ValidationError.NoMatchingTransformFound(path, transformName));
@@ -180,15 +193,21 @@ private ValidateOf<String> transformString(String path, String input) {
                 }
 
                 if (!foundTransformer) {
-                    return ValidateOf.inValid(new ValidationError.NoMatchingDefaultTransformFound(path, key));
+                    // if we have no results from the transform but a default value, use the default
+                    if (defaultValue != null) {
+                        foundMatch = true;
+                        newLeafValue.append(defaultValue);
+                    } else {
+                        return ValidateOf.inValid(new ValidationError.NoMatchingDefaultTransformFound(path, key));
+                    }
                 }
             }
         }
 
         if (foundMatch) {
             return ValidateOf.valid(newLeafValue.toString());
         } else {
-            return ValidateOf.valid(input);
+            return ValidateOf.inValid(new ValidationError.TransformDoesntMatchRegex(path, input));
         }
     }
 }
diff --git a/...t/java/org/github/gestalt/config/post/process/transform/TransformerPostProcessorTest.java b/...t/java/org/github/gestalt/config/post/process/transform/TransformerPostProcessorTest.java
@@ -81,6 +81,61 @@ void processTextWithMultipleTransform() {
         Assertions.assertEquals("hello world it is sunny today", validateNode.results().getValue().get());
     }
 
+    @Test
+    void processTextWithMultipleDefaults() {
+
+        Map<String, String> customMap = new HashMap<>();
+        CustomMapTransformer transformer = new CustomMapTransformer(customMap);
+
+        TransformerPostProcessor transformerPostProcessor = new TransformerPostProcessor(Collections.singletonList(transformer));
+        LeafNode node = new LeafNode("hello ${map:place:=world} it is ${weather:=sunny} today");
+        ValidateOf<ConfigNode> validateNode = transformerPostProcessor.process("location", node);
+
+        Assertions.assertFalse(validateNode.hasErrors());
+        Assertions.assertTrue(validateNode.hasResults());
+        Assertions.assertTrue(validateNode.results().getValue().isPresent());
+        Assertions.assertEquals("hello world it is sunny today", validateNode.results().getValue().get());
+    }
+
+    @Test
+    void processTextWithMultipleDefaultsButHasValues() {
+
+        Map<String, String> customMap = new HashMap<>();
+        customMap.put("place", "world");
+        customMap.put("weather", "sunny");
+        CustomMapTransformer transformer = new CustomMapTransformer(customMap);
+
+        TransformerPostProcessor transformerPostProcessor = new TransformerPostProcessor(Collections.singletonList(transformer));
+        LeafNode node = new LeafNode("hello ${map:place:=earth} it is ${weather:=overcast} today");
+        ValidateOf<ConfigNode> validateNode = transformerPostProcessor.process("location", node);
+
+        Assertions.assertFalse(validateNode.hasErrors());
+        Assertions.assertTrue(validateNode.hasResults());
+        Assertions.assertTrue(validateNode.results().getValue().isPresent());
+        Assertions.assertEquals("hello world it is sunny today", validateNode.results().getValue().get());
+    }
+
+    @Test
+    void processInvalidFormat() {
+        // not sure about this test, this isnt "intended" behaviour. It just happens to happen.
+
+        Map<String, String> customMap = new HashMap<>();
+        customMap.put("place", "world");
+        customMap.put("weather", "sunny");
+        CustomMapTransformer transformer = new CustomMapTransformer(customMap);
+
+        TransformerPostProcessor transformerPostProcessor = new TransformerPostProcessor(Collections.singletonList(transformer));
+        LeafNode node = new LeafNode("${map:place:world}");
+        ValidateOf<ConfigNode> validateNode = transformerPostProcessor.process("location", node);
+
+        Assertions.assertTrue(validateNode.hasErrors());
+        Assertions.assertEquals(1, validateNode.getErrors().size());
+        Assertions.assertEquals("Transform doesnt match the expected format with value map:place:world on path location",
+            validateNode.getErrors().get(0).description());
+        Assertions.assertEquals(ValidationLevel.ERROR, validateNode.getErrors().get(0).level());
+
+    }
+
     @Test
     void processNoValue() {
         Map<String, String> customMap = new HashMap<>();

diff --git a/gestalt-core/src/test/resources/defaultPPEnv.properties b/gestalt-core/src/test/resources/defaultPPEnv.properties
@@ -5,8 +5,8 @@ db.hosts[1].url=jdbc:postgresql://localhost:5432/mydb2
 db.hosts[2].user=credmond
 db.hosts[2].url=jdbc:postgresql://localhost:5432/mydb3
 db.ConnectionTimeout=6000
-db.idleTimeout=${envVar:DB_IDLETIMEOUT}
-db.maxLifetime=60000.0
+db.idleTimeout=${envVar:DB_IDLETIMEOUT:=900}
+db.maxLifetime=${envVar:NO_RESULTS_FOUND:=60000.0}
 http.Pool.maxTotal=100
 http.Pool.maxPerRoute=10
 http.Pool.validateAfterInactivity=6000

diff --git a/gestalt-examples/gestalt-sample/src/test/resources/defaultPPEnv.properties b/gestalt-examples/gestalt-sample/src/test/resources/defaultPPEnv.properties
@@ -5,8 +5,8 @@ db.hosts[1].url=jdbc:postgresql://localhost:5432/mydb2
 db.hosts[2].user=credmond
 db.hosts[2].url=jdbc:postgresql://localhost:5432/mydb3
 db.ConnectionTimeout=6000
-db.idleTimeout=${envVar:DB_IDLETIMEOUT}
-db.maxLifetime=60000.0
+db.idleTimeout=${envVar:DB_IDLETIMEOUT:=900}
+db.maxLifetime=${envVar:NO_RESULTS_FOUND:=60000.0}
 http.Pool.maxTotal=100
 http.Pool.maxPerRoute=10
 http.Pool.validateAfterInactivity=6000

diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
@@ -1,20 +1,20 @@
 [versions]
 java = "11"
 javaLatest = "19"
-kotlin = "1.8.20"
+kotlin = "1.8.21"
 kotlinDokka = "1.8.10"
 kodeinDI = "7.20.1"
 koinDI= "3.4.0"
 
-jackson = "2.14.2"
+jackson = "2.15.0"
 
 guice = "5.1.0"
 cdi = "3.0.0"
 weld = "3.1.0.Final"
 weldCore = "4.0.3.Final"
 
 hocon = "1.4.2"
-aws = "2.20.48"
+aws = "2.20.52"
 jgit = "6.5.0.202303070854-r"
 
 eddsa = "0.3.0"
@@ -23,7 +23,7 @@ junit5 = "5.9.2"
 assertJ = "3.24.2"
 mockito = "5.2.0"
 mockk = "1.13.5"
-koTestAssertions = "5.5.5"
+koTestAssertions = "5.6.1"
 awsMock = "2.11.0"
 
 errorprone = "2.18.0"
@@ -37,7 +37,7 @@ pmd = "6.54.0"
 jmh = "1.36"
 gradleJmh = "0.7.1"
 
-gestalt = "0.20.3"
+gestalt = "0.20.5"
 
 gradleVersions = "0.46.0"
 gitVersions = "2.0.0"