Add a way to take a consumer of a writer in the FileManifest (smithy-lang#2599)

* Add a way to take a consumer of a writer in the FileManifest

* Expand introduced start import

* Move the default implementation to the interface

* Apply spotless

Author: sugmanue

smithy-build/src/main/java/software/amazon/smithy/build/FileManifest.java

@@ -8,10 +8,13 @@
 import java.io.InputStream;
 import java.io.Reader;
 import java.io.StringReader;
+import java.io.Writer;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Consumer;
 import java.util.stream.Collectors;
 import software.amazon.smithy.model.node.Node;
 
@@ -212,7 +215,8 @@ default Path writeFile(String path, InputStream fileContentsInputStream) {
      */
     @SuppressWarnings("unused")
     default Path writeJson(Path path, Node node) {
-        return writeFile(path, Node.prettyPrintJson(node).trim() + "\n");
+        writeUsing(path, (writer) -> Node.prettyPrintJsonToWriter(node, writer));
+        return path;
     }
 
     /**
@@ -227,6 +231,23 @@ default Path writeJson(String path, Node node) {
         return writeJson(Paths.get(path), node);
     }
 
+    /**
+     * Adds a file to the result generated by passing a writer to the consumer.
+     *
+     * @param path Relative path to write to.
+     * @param consumer Node data to write to JSON.
+     */
+    default void writeUsing(Path path, Consumer<Writer> consumer) {
+        path = addFile(path);
+
+        try (Writer writer = Files.newBufferedWriter(path)) {
+            consumer.accept(writer);
+            writer.write('\n');
+        } catch (IOException e) {
+            throw new SmithyBuildException("Unable to create a write to file `" + path + "`: " + e.getMessage(), e);
+        }
+    }
+
     /**
      * Checks if the given file is stored in the manifest.
      *

smithy-build/src/main/java/software/amazon/smithy/build/MockManifest.java

@@ -8,6 +8,8 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
+import java.io.StringWriter;
+import java.io.Writer;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.InvalidPathException;
@@ -19,6 +21,7 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.ConcurrentSkipListMap;
+import java.util.function.Consumer;
 
 /**
  * A {@link FileManifest} that doesn't actually store files on disk.
@@ -128,6 +131,13 @@ public Path writeFile(Path path, InputStream fileContentsInputStream) {
         }
     }
 
+    @Override
+    public void writeUsing(Path path, Consumer<Writer> consumer) {
+        Writer writer = new StringWriter();
+        consumer.accept(writer);
+        writeFile(path, writer.toString());
+    }
+
     /**
      * Gets the contents of a stored file as a String.
      *

smithy-model/src/main/java/software/amazon/smithy/model/node/Node.java

@@ -7,6 +7,7 @@
 import static java.lang.String.format;
 
 import java.io.InputStream;
+import java.io.Writer;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Comparator;
@@ -144,6 +145,27 @@ public static String prettyPrintJson(Node node, String indentString) {
         return NodeHandler.prettyPrint(node, indentString);
     }
 
+    /**
+     * Writes the contents of a pretty-printed Node to the given writer.
+     *
+     * @param node Node to write.
+     * @param writer Writer to write to.
+     */
+    public static void prettyPrintJsonToWriter(Node node, Writer writer) {
+        NodeHandler.prettyPrintToWriter(node, "    ", writer);
+    }
+
+    /**
+     * Writes the contents of a pretty-printed Node to the given writer.
+     *
+     * @param node Node to write.
+     * @param indentString String to use for indention.
+     * @param writer Writer to write to.
+     */
+    public static void prettyPrintJsonToWriter(Node node, String indentString, Writer writer) {
+        NodeHandler.prettyPrintToWriter(node, indentString, writer);
+    }
+
     /**
      * Writes the contents of a Node to a non-pretty-printed JSON string.
      *

smithy-model/src/main/java/software/amazon/smithy/model/node/internal/NodeHandler.java

@@ -5,6 +5,7 @@
 package software.amazon.smithy.model.node.internal;
 
 import java.io.StringWriter;
+import java.io.Writer;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import software.amazon.smithy.model.SourceLocation;
@@ -45,6 +46,12 @@ public static String prettyPrint(Node node, String indentString) {
         return writer.toString();
     }
 
+    @SmithyInternalApi
+    public static void prettyPrintToWriter(Node node, String indentString, Writer writer) {
+        JsonWriter jsonWriter = new PrettyPrintWriter(writer, indentString);
+        node.accept(new NodeWriter(jsonWriter));
+    }
+
     @Override
     void endNull(SourceLocation location) {
         value = new NullNode(location);