feat(app): load YAML element templates

* Uses `js-yaml` to transform YAML files to JSON element templates

app/lib/config/__tests__/config-spec.js

@@ -155,8 +155,11 @@ describe('Config', function() {
       // then
       expect(templates).to.eql([
         { id: 'com.foo.Bar' }, // local
+        { id: 'com.yml.Bar' }, // local (YAML)
         { id: 'com.foo.Bar', FOO: 'BAR' }, // global
-        { id: 'single', FOO: 'BAR' } // global
+        { id: 'single', FOO: 'BAR' }, // global
+        { id: 'com.yml.Bar', FOO: 'BAR' }, // global (YAML)
+        { id: 'single-yml', FOO: 'BAR' } // global (YAML)
       ]);
     });
 
@@ -181,7 +184,9 @@ describe('Config', function() {
       // then
       expect(templates).to.eql([
         { id: 'com.foo.Bar', FOO: 'BAR' },
-        { id: 'single', FOO: 'BAR' }
+        { id: 'single', FOO: 'BAR' },
+        { id: 'com.yml.Bar', FOO: 'BAR' },
+        { id: 'single-yml', FOO: 'BAR' }
       ]);
     });
 
@@ -203,6 +208,24 @@ describe('Config', function() {
         .to.throw(/template .* parse error: Unexpected token I.*/);
     });
 
+
+    it('should throw if YML#load errors', function() {
+
+      // given
+      const file = null;
+
+      const config = new Config({
+        resourcesPaths: [
+          getAbsolutePath('fixtures/broken-yml')
+        ],
+        userPath: 'foo'
+      });
+
+      // when
+      expect(() => config.get('bpmn.elementTemplates', file))
+        .to.throw(/template .* parse error: end of the stream or a document separator is expected */);
+    });
+
   });
 
 

app/lib/config/__tests__/fixtures/broken-yml/element-templates/broken.yml

@@ -0,0 +1,2 @@
+text foobar
+number: 2

app/lib/config/__tests__/fixtures/ok/element-templates/list.yml

@@ -0,0 +1,2 @@
+- id: com.yml.Bar
+  FOO: BAR

app/lib/config/__tests__/fixtures/ok/element-templates/single.yml

@@ -0,0 +1,2 @@
+id: single-yml
+FOO: BAR

app/lib/config/__tests__/fixtures/project/.camunda/element-templates/list.yml

@@ -0,0 +1 @@
+- id: com.yml.Bar

app/lib/config/providers/ElementTemplatesProvider.js

@@ -13,10 +13,17 @@ const glob = require('glob');
 const parents = require('parents');
 const path = require('path');
 
-const { isArray } = require('min-dash');
+const { flatten, isArray, keys } = require('min-dash');
+
+const YAML = require('js-yaml');
 
 const log = require('../../log')('app:config:element-templates');
 
+const FILE_HANDLERS = {
+  'json': getJSONTemplatesForPath,
+  'yml': getYAMLTemplatesForPath
+};
+
 
 /**
  * Get element templates.
@@ -80,7 +87,9 @@ function getTemplates(paths) {
 
     // do not throw if file not accessible or no such file
     try {
-      files = globTemplates(path);
+      files = flatten(keys(FILE_HANDLERS).map(type => {
+        return globTemplates(path, type);
+      }));
     } catch (error) {
       log.error(`templates ${ path } glob error`, error);
 
@@ -105,19 +114,24 @@ function getTemplatesForPaths(paths) {
   return paths.reduce((templates, path) => {
     return [
       ...templates,
-      ...getTemplatesForPath(path)
+      ...getFileHandler(path)(path)
     ];
   }, []);
 }
 
+function getFileHandler(file) {
+  const extension = path.extname(file).slice(1);
+  return FILE_HANDLERS[extension];
+}
+
 /**
  * Get element templates from paths.
  *
  * @param  {string} path
  *
  * @return {Array<Template>}
  */
-function getTemplatesForPath(path) {
+function getJSONTemplatesForPath(path) {
   let templates;
 
   try {
@@ -139,15 +153,41 @@ function getTemplatesForPath(path) {
  * Glob element templates from `<path>/resources`.
  *
  * @param {string} path
+ * @param {string} type
  *
  * @return {Array<string>}
  */
-function globTemplates(path) {
+function globTemplates(path, type) {
   const globOptions = {
     cwd: path,
     nodir: true,
     realpath: true
   };
 
-  return glob.sync('element-templates/**/*.json', globOptions);
+  return glob.sync('element-templates/**/*.' + type, globOptions);
+}
+
+/**
+ * Get element templates from paths.
+ *
+ * @param  {string} path
+ *
+ * @return {Array<Template>}
+ */
+function getYAMLTemplatesForPath(path) {
+  let templates;
+
+  try {
+    templates = YAML.load(fs.readFileSync(path, 'utf8'));
+
+    if (!isArray(templates)) {
+      templates = [ templates ];
+    }
+
+    return templates;
+  } catch (error) {
+    log.error(`template ${ path } parse error`, error);
+
+    throw new Error(`template ${ path } parse error: ${ error.message }`);
+  }
 }

app/package.json

@@ -15,6 +15,7 @@
     "form-data": "^2.5.1",
     "glob": "^7.1.6",
     "ids": "^1.0.0",
+    "js-yaml": "^4.1.0",
     "min-dash": "^3.8.1",
     "mri": "^1.1.6",
     "node-fetch": "^2.6.1",