diff --git a/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/TestExecutionReportFormatter.kt b/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/TestExecutionReportFormatter.kt
new file mode 100644
index 0000000..e9a87db
--- /dev/null
+++ b/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/TestExecutionReportFormatter.kt
@@ -0,0 +1,7 @@
+package io.github.platan.tests_execution_chart.reporters
+
+import io.github.platan.tests_execution_chart.report.data.TestExecutionScheduleReport
+
+interface TestExecutionReportFormatter {
+    fun format(report: TestExecutionScheduleReport): String
+}
diff --git a/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/json/JsonReporter.kt b/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/json/JsonReporter.kt
index 5188b88..001641d 100644
--- a/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/json/JsonReporter.kt
+++ b/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/json/JsonReporter.kt
@@ -3,21 +3,16 @@ package io.github.platan.tests_execution_chart.reporters.json
 import io.github.platan.tests_execution_chart.report.ReportConfig
 import io.github.platan.tests_execution_chart.report.data.TestExecutionScheduleReport
 import io.github.platan.tests_execution_chart.reporters.GanttDiagramReporter
-import kotlinx.serialization.encodeToString
-import kotlinx.serialization.json.Json
 import java.io.File
 
 class JsonReporter : GanttDiagramReporter<JsonConfig>() {
-    private val json = Json {
-        prettyPrint = true
-    }
 
     override fun report(
         report: TestExecutionScheduleReport,
         baseDir: File,
         taskName: String
     ) {
-        val jsonReport = json.encodeToString(report)
+        val jsonReport = JsonTestExecutionReportFormatter().format(report)
         val reportFile = save(jsonReport, taskName, baseDir, config.outputLocation, "json")
         logger.lifecycle("Tests execution schedule report saved to ${reportFile.absolutePath} file.")
     }
diff --git a/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/json/JsonTestExecutionReportFormatter.kt b/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/json/JsonTestExecutionReportFormatter.kt
new file mode 100644
index 0000000..4fbbf12
--- /dev/null
+++ b/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/json/JsonTestExecutionReportFormatter.kt
@@ -0,0 +1,16 @@
+package io.github.platan.tests_execution_chart.reporters.json
+
+import io.github.platan.tests_execution_chart.report.data.TestExecutionScheduleReport
+import io.github.platan.tests_execution_chart.reporters.TestExecutionReportFormatter
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+
+class JsonTestExecutionReportFormatter : TestExecutionReportFormatter {
+    private val json = Json {
+        prettyPrint = true
+    }
+
+    override fun format(report: TestExecutionScheduleReport): String {
+        return json.encodeToString(report)
+    }
+}
\ No newline at end of file
diff --git a/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/mermaid/TestExecutionMermaidDiagramFormatter.kt b/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/mermaid/TestExecutionMermaidDiagramFormatter.kt
index 4c92857..9c155e5 100644
--- a/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/mermaid/TestExecutionMermaidDiagramFormatter.kt
+++ b/tests-execution-chart-commons/src/main/kotlin/io/github/platan/tests_execution_chart/reporters/mermaid/TestExecutionMermaidDiagramFormatter.kt
@@ -2,10 +2,11 @@ package io.github.platan.tests_execution_chart.reporters.mermaid
 
 import io.github.platan.tests_execution_chart.report.data.TestExecutionScheduleReport
 import io.github.platan.tests_execution_chart.report.data.TimedTestResult
+import io.github.platan.tests_execution_chart.reporters.TestExecutionReportFormatter
 import io.github.platan.tests_execution_chart.reporters.mermaid.core.MermaidGanttDiagram
 import io.github.platan.tests_execution_chart.reporters.mermaid.core.MermaidGanttDiagramFormatter
 
-class TestExecutionMermaidDiagramFormatter {
+class TestExecutionMermaidDiagramFormatter : TestExecutionReportFormatter {
 
     companion object {
         val taskFormat: Map<TimedTestResult.Type, Map<String, String>> = mapOf(
@@ -14,7 +15,7 @@ class TestExecutionMermaidDiagramFormatter {
         )
     }
 
-    fun format(report: TestExecutionScheduleReport): String {
+    override fun format(report: TestExecutionScheduleReport): String {
         val diagramBuilder = MermaidGanttDiagram.MermaidGanttDiagramBuilder()
         report.results.groupBy { result -> result.className }.forEach { (className, results) ->
             diagramBuilder.addSection(className.orEmpty())
diff --git a/tests-execution-chart-commons/src/test/groovy/io/github/platan/tests_execution_chart/reporters/json/JsonTestExecutionReportFormatterTest.groovy b/tests-execution-chart-commons/src/test/groovy/io/github/platan/tests_execution_chart/reporters/json/JsonTestExecutionReportFormatterTest.groovy
new file mode 100644
index 0000000..7616978
--- /dev/null
+++ b/tests-execution-chart-commons/src/test/groovy/io/github/platan/tests_execution_chart/reporters/json/JsonTestExecutionReportFormatterTest.groovy
@@ -0,0 +1,29 @@
+package io.github.platan.tests_execution_chart.reporters.json
+
+import io.github.platan.tests_execution_chart.report.TestExecutionScheduleReportBuilder
+import spock.lang.Specification
+import spock.lang.Subject
+
+class JsonTestExecutionReportFormatterTest extends Specification {
+
+    @Subject
+    def formatter = new JsonTestExecutionReportFormatter()
+
+    def "should format empty report"() {
+        given:
+        def emptyReport = new TestExecutionScheduleReportBuilder().getResults()
+
+        when:
+        def result = formatter.format(emptyReport)
+
+        then:
+        result ==
+                """{
+                |    "results": [
+                |    ],
+                |    "marks": [
+                |    ]
+                |}""".stripMargin()
+    }
+
+}