1 files changed, 75 insertions, 0 deletions
diff --git a/testutil/src/main/java/com/yahoo/test/json/JsonBuilder.java b/testutil/src/main/java/com/yahoo/test/json/JsonBuilder.java
new file mode 100644
index 00000000000..bbb8586a290
--- /dev/null
+++ b/testutil/src/main/java/com/yahoo/test/json/JsonBuilder.java
@@ -0,0 +1,75 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.test.json;
+
+import com.fasterxml.jackson.core.io.JsonStringEncoder;
+
+/**
+ * String buffer for building a formatted JSON.
+ *
+ * @author hakonhall
+ */
+class JsonBuilder {
+    private final JsonStringEncoder jsonStringEncoder = JsonStringEncoder.getInstance();
+    private final StringBuilder builder = new StringBuilder();
+    private final String indentation;
+    private final boolean multiLine;
+    private final String colon;
+
+    private boolean bol = true;
+    private int level = 0;
+
+    static JsonBuilder forCompactJson() { return new JsonBuilder(0, true); }
+    static JsonBuilder forMultiLineJson(int spacesPerIndent) { return new JsonBuilder(spacesPerIndent, false); }
+
+    JsonBuilder(int spacesPerIndent, boolean compact) {
+        this.indentation = compact ? "" : " ".repeat(spacesPerIndent);
+        this.multiLine = !compact;
+        this.colon = compact ? ":" : ": ";
+    }
+
+    void appendLineAndIndent(String text) { appendLineAndIndent(text, 0); }
+
+    void newLineIndentAndAppend(int levelShift, String text) {
+        appendNewLine();
+        indent(levelShift);
+        append(text);
+    }
+
+    void appendLineAndIndent(String text, int levelShift) {
+        appendLine(text);
+        indent(levelShift);
+        append("");
+    }
+
+    void appendColon() { builder.append(colon); }
+
+    void appendStringValue(String rawString) {
+        builder.append('"');
+        jsonStringEncoder.quoteAsString(rawString, builder);
+        builder.append('"');
+    }
+
+    void append(String textWithoutNewline) {
+        if (bol) {
+            builder.append(indentation.repeat(level));
+            bol = false;
+        }
+
+        builder.append(textWithoutNewline);
+    }
+
+    private void indent(int levelShift) { level += levelShift; }
+
+    private void appendLine(String text) {
+        append(text);
+        appendNewLine();
+    }
+
+    private void appendNewLine() {
+        if (multiLine) builder.append('\n');
+        bol = true;
+    }
+
+    @Override
+    public String toString() { return builder.toString(); }
+}