add unit tests for load()/save() of DataSets

Author: Gubaer

src/main/javascript/v2/josm/ds.js

@@ -500,8 +500,8 @@ class DataSetUtil {
    *   <dd class="param-desc">one of the strings <code>osm</code> (Open Street Map XML data),
    *   <code>osc</code> (Open Street Map change format), or
    *   <code>osm.gz</code> (Open Street Map XML data,
-   *   compressed with gzip).  format is normalized by removing leading and
-   *   trailing whitespace and conversion to lower case.</dd>
+   *   compressed with gzip).  The format is normalized: white space is removed and it is
+   *   converted to lower case.</dd>
    * </dl>
    *
    * @example
@@ -515,6 +515,8 @@ class DataSetUtil {
    *
    * @param {string|java.io.File}  source  the data source
    * @param {object} [options]  optional named parameters
+   *
+   * @return {module:josm/ds~DataSetUtil} the data set util with the loaded data set
    */
   static load (source, options) {
     function normalizeFile (source) {

src/test/unit/groovy/org/openstreetmap/josm/plugins/scripting/graalvm/api/DataSetInputOutputTest.groovy

@@ -0,0 +1,106 @@
+package org.openstreetmap.josm.plugins.scripting.graalvm.api
+
+import org.junit.jupiter.api.AfterEach
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import org.openstreetmap.josm.plugins.scripting.graalvm.AbstractGraalVMBasedTest
+import org.openstreetmap.josm.plugins.scripting.graalvm.GraalVMFacadeFactory
+import org.openstreetmap.josm.plugins.scripting.graalvm.IGraalVMFacade
+
+class DataSetInputOutputTest extends AbstractGraalVMBasedTest{
+    private IGraalVMFacade facade
+
+    @BeforeEach
+    void initGraalVMFacade() {
+        facade = GraalVMFacadeFactory.getOrCreateGraalVMFacade()
+    }
+
+    @AfterEach
+    void resetGraalVMFacade() {
+        if (facade != null) {
+            facade.resetContext()
+        }
+    }
+
+    @Test
+    void "can load an osm file - default options"() {
+        final file = new File(
+            getProjectHome(),
+            "src/test/resources/sample-data-files/test-josm-open.osm")
+
+        final src = """
+        const josm = require('josm')
+        const {DataSetUtil} = require('josm/ds')
+        
+        DataSetUtil.load('$file.absolutePath')
+        """
+        facade.eval(graalJSDescriptor, src)
+    }
+
+    @Test
+    void "can load an osm file, with File object - default options"() {
+        final file = new File(
+                getProjectHome(),
+                "src/test/resources/sample-data-files/test-josm-open.osm")
+
+        final src = """
+        const josm = require('josm')
+        const {DataSetUtil} = require('josm/ds')
+        const File = Java.type('java.io.File')
+        const file = new File('$file.absolutePath')
+        DataSetUtil.load(file)
+        """
+        facade.eval(graalJSDescriptor, src)
+    }
+
+    @Test
+    void "can load an osm file - with format option"() {
+        final file = new File(
+                getProjectHome(),
+                "src/test/resources/sample-data-files/test-josm-open.osm")
+
+        final src = """
+        const josm = require('josm')
+        const {DataSetUtil} = require('josm/ds')
+        
+        DataSetUtil.load('$file.absolutePath', {format: 'osm'})
+        """
+        facade.eval(graalJSDescriptor, src)
+    }
+
+    @Test
+    void "should fail if format isn't matching with content"() {
+        final file = new File(
+            getProjectHome(),
+            "src/test/resources/sample-data-files/test-josm-open.osm")
+
+        final src = """
+        const josm = require('josm')
+        const {DataSetUtil} = require('josm/ds')
+        
+        DataSetUtil.load('$file.absolutePath', {format: 'osm.gz'})
+        """
+        shouldFail(Throwable) {
+            facade.eval(graalJSDescriptor, src)
+        }
+    }
+
+    @Test
+    void "can load a file, save it, and load it again"() {
+        final file = new File(
+            getProjectHome(),
+            "src/test/resources/sample-data-files/test-josm-open.osm")
+        final tempOutputFile = File.createTempFile("test-josm-open", ".tmp")
+
+        final src = """
+        const josm = require('josm')
+        const {DataSetUtil} = require('josm/ds')
+        
+        const loadedData = DataSetUtil.load('$file.absolutePath')
+        loadedData.save('$tempOutputFile.absolutePath')
+        const loadedAgain = DataSetUtil.load('$tempOutputFile.absolutePath', {format: 'osm'})
+        """
+        facade.eval(graalJSDescriptor, src)
+    }
+
+}