collapse empty arrays and objects when print json (#81)

Author: MykolaGolubyev

webtau-http/src/main/java/com/twosigma/webtau/http/render/DataNodeAnsiPrinter.java

@@ -69,6 +69,19 @@ private void printNode(DataNode dataNode, boolean skipIndent) {
     }
 
     private void printObject(DataNode dataNode, boolean skipIndent) {
+        if (dataNode.numberOfChildren() == 0) {
+            printEmptyObject();
+        } else {
+            printNotEmptyObject(dataNode, skipIndent);
+        }
+    }
+
+    private void printEmptyObject() {
+        printDelimiter("{");
+        printDelimiter("}");
+    }
+
+    private void printNotEmptyObject(DataNode dataNode, boolean skipIndent) {
         Map<String, DataNode> children = dataNode.asMap();
 
         openScope("{", skipIndent);
@@ -96,10 +109,23 @@ private void printObject(DataNode dataNode, boolean skipIndent) {
     }
 
     private void printList(DataNode dataNode, boolean skipIndent) {
+        if (dataNode.elements().isEmpty()) {
+            printEmptyList();
+        } else {
+            printNonEmptyList(dataNode, skipIndent);
+        }
+    }
+
+    private void printEmptyList() {
+        printDelimiter("[");
+        printDelimiter("]");
+    }
+
+    private void printNonEmptyList(DataNode dataNode, boolean skipIndent) {
         openScope("[", skipIndent);
 
-        int idx = 0;
         int size = dataNode.elements().size();
+        int idx = 0;
         for (DataNode n : dataNode.elements()) {
             printNode(n, false);
 
@@ -216,6 +242,10 @@ private String indentation() {
     }
 
     private static String indent(final int nestLevel) {
+        if (nestLevel == 0) {
+            return "";
+        }
+
         return StringUtils.leftPad(" ", nestLevel * 2);
     }
 

webtau-http/src/test/groovy/com/twosigma/webtau/http/render/DataNodeAnsiPrinterTest.groovy

@@ -16,18 +16,23 @@
 
 package com.twosigma.webtau.http.render
 
+import com.twosigma.webtau.console.ConsoleOutput
 import com.twosigma.webtau.console.ConsoleOutputs
 import com.twosigma.webtau.console.ansi.AnsiConsoleOutput
+import com.twosigma.webtau.console.ansi.Color
+import com.twosigma.webtau.console.ansi.FontStyle
 import com.twosigma.webtau.http.datanode.DataNodeBuilder
 import com.twosigma.webtau.http.datanode.DataNodeId
 import org.junit.AfterClass
+import org.junit.Assert
 import org.junit.BeforeClass
 import org.junit.Test
 
 import static com.twosigma.webtau.Ddjt.equal
 
 class DataNodeAnsiPrinterTest {
     private static def ansiConsoleOutput = new AnsiConsoleOutput()
+
     @BeforeClass
     static void init() {
         ConsoleOutputs.add(ansiConsoleOutput)
@@ -40,16 +45,44 @@ class DataNodeAnsiPrinterTest {
 
     @Test
     void "should print list data node with indentation and using different colors"() {
-        new DataNodeAnsiPrinter().print(DataNodeBuilder.fromList(new DataNodeId("root"), [1, 2, 3, 4]))
+        def textOnly = withCapturedOutput {
+            new DataNodeAnsiPrinter().print(DataNodeBuilder.fromList(new DataNodeId("root"), [1, 2, 3, 4]))
+        }
+
+        Assert.assertEquals('[\n' +
+                '  1,\n' +
+                '  2,\n' +
+                '  3,\n' +
+                '  4\n' +
+                ']', textOnly)
     }
 
     @Test
     void "should print object data node"() {
-        new DataNodeAnsiPrinter().print(DataNodeBuilder.fromMap(new DataNodeId("root"), [
-                key1: 'value1',
-                key2: 'value2',
-                key3: [key31: 'value31', key32: [5, 6, 8]],
-                key4: [key41: 'value41', key42: 'value42']]))
+        def textOnly = withCapturedOutput {
+            new DataNodeAnsiPrinter().print(DataNodeBuilder.fromMap(new DataNodeId("root"), [
+                    key1: 'value1',
+                    key2: 'value2',
+                    key3: [key31: 'value31', key32: [5, 6, 8]],
+                    key4: [key41: 'value41', key42: 'value42']]))
+        }
+
+        Assert.assertEquals('{\n' +
+                '  "key1": "value1",\n' +
+                '  "key2": "value2",\n' +
+                '  "key3": {\n' +
+                '    "key31": "value31",\n' +
+                '    "key32": [\n' +
+                '      5,\n' +
+                '      6,\n' +
+                '      8\n' +
+                '    ]\n' +
+                '  },\n' +
+                '  "key4": {\n' +
+                '    "key41": "value41",\n' +
+                '    "key42": "value42"\n' +
+                '  }\n' +
+                '}', textOnly)
     }
 
     @Test
@@ -71,6 +104,80 @@ class DataNodeAnsiPrinterTest {
             // catch as it is an expected here and serves to check if the value will be rendered as failed
         }
 
-        new DataNodeAnsiPrinter().print(dataNode)
+        def textOnly = withCapturedOutput {
+            new DataNodeAnsiPrinter().print(dataNode)
+        }
+
+        Assert.assertEquals('[\n' +
+                '  {\n' +
+                '    "key1": "value1",\n' +
+                '    "key2": __"value2"__,\n' +
+                '    "key3": {\n' +
+                '      "key31": **"value31"**,\n' +
+                '      "key32": [\n' +
+                '        5,\n' +
+                '        6,\n' +
+                '        8\n' +
+                '      ]\n' +
+                '    }\n' +
+                '  },\n' +
+                '  {\n' +
+                '    "key4": "value4",\n' +
+                '    "key5": "value5"\n' +
+                '  }\n' +
+                ']', textOnly)
+    }
+
+    @Test
+    void "should collapse empty list and object"() {
+        def textOnly = withCapturedOutput {
+            new DataNodeAnsiPrinter().print(DataNodeBuilder.fromMap(new DataNodeId("root"), [
+                    key1: 'value1',
+                    key2: 'value2',
+                    key3: [],
+                    key4: [:]]))
+        }
+
+        Assert.assertEquals('{\n' +
+                '  "key1": "value1",\n' +
+                '  "key2": "value2",\n' +
+                '  "key3": [],\n' +
+                '  "key4": {}\n' +
+                '}', textOnly)
+    }
+
+    private static String withCapturedOutput(Closure code) {
+        def capture = new CaptureOutput()
+        try {
+            ConsoleOutputs.add(capture)
+            code()
+
+            return capture.textOnly
+        } finally {
+            ConsoleOutputs.remove(capture)
+        }
+    }
+
+    private static class CaptureOutput implements ConsoleOutput {
+        private def stylesAndOutput = []
+        private def textLInes = []
+
+        @Override
+        void out(Object... styleOrValues) {
+            def line = Arrays.asList(styleOrValues).findAll {
+                !(it instanceof Color) && !(it instanceof FontStyle)
+            }.join('')
+
+            textLInes.add(line)
+            stylesAndOutput.addAll(Arrays.asList(styleOrValues))
+        }
+
+        String getTextOnly() {
+            return textLInes.join('\n')
+        }
+
+        @Override
+        void err(Object... styleOrValues) {
+        }
     }
 }