feat: resolve variables from function definition

Related to bpmn-io/dmn-js#853

lib/core.js

@@ -27,6 +27,8 @@ export function resolveVariables(moddleElement) {
 function handle(element, context) {
   if (is(element, 'dmn:Decision')) {
     handleDecision(element, context);
+  } else if (is(element, 'dmn:Expression')) {
+    handleExpression(element, context);
   }
 }
 
@@ -187,6 +189,40 @@ function handleBusinessKnowledgeModel(bkm, context) {
   context.variables.push(variable);
 }
 
+function handleExpression(expression, context) {
+  if (is(expression, 'dmn:FunctionDefinition')) {
+    handleFunctionDefinition(expression, context);
+  }
+}
+
+function handleFunctionDefinition(functionDefinition, context) {
+  const parameters = functionDefinition.get('formalParameter');
+
+  for (const parameter of parameters) {
+    handleFormalParameter(parameter, context);
+  }
+}
+
+function handleFormalParameter(parameter, context) {
+  const name = parameter.get('name');
+
+  // prevent invalid variables in suggestions
+  if (!name) {
+    return;
+  }
+
+  /** @type Variable */
+  const variable = {
+    name,
+    origin: parameter
+  };
+
+  if (parameter.get('typeRef')) {
+    variable.detail = parameter.get('typeRef');
+  }
+
+  context.variables.push(variable);
+}
 
 
 // helpers //////////////////////

test/fixtures/function-definition.dmn

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<definitions xmlns="https://www.omg.org/spec/DMN/20191111/MODEL/" xmlns:dmndi="https://www.omg.org/spec/DMN/20191111/DMNDI/" xmlns:dc="http://www.omg.org/spec/DMN/20180521/DC/" xmlns:modeler="http://camunda.org/schema/modeler/1.0" xmlns:di="http://www.omg.org/spec/DMN/20180521/DI/" id="Definitions_0zw4l66" name="DRD" namespace="http://camunda.org/schema/1.0/dmn" exporter="Camunda Modeler" exporterVersion="5.9.0" modeler:executionPlatform="Camunda Cloud" modeler:executionPlatformVersion="8.1.0">
+  <businessKnowledgeModel name="BKM" id="Bkm_1">
+    <encapsulatedLogic>
+      <formalParameter name="noType" />
+      <formalParameter name="string" typeRef="string" />
+      <formalParameter name="num" typeRef="number" />
+      <literalExpression>
+        <text>noType + num - string</text>
+      </literalExpression>
+    </encapsulatedLogic>
+  </businessKnowledgeModel>
+  <dmndi:DMNDI>
+    <dmndi:DMNDiagram>
+      <dmndi:DMNShape dmnElementRef="Bkm_1">
+        <dc:Bounds height="80" width="180" x="160" y="100" />
+      </dmndi:DMNShape>
+    </dmndi:DMNDiagram>
+  </dmndi:DMNDI>
+</definitions>

test/spec/core.spec.js

@@ -4,6 +4,7 @@ import SimpleDmn from '../fixtures/simple.dmn';
 import RequiredDecisionDmn from '../fixtures/required-decision.dmn';
 import RequiredKnowledgeDmn from '../fixtures/required-knowledge.dmn';
 import MissingNamesDmn from '../fixtures/missing-names.dmn';
+import FunctionDefinitionDmn from '../fixtures/function-definition.dmn';
 
 import { resolveVariables } from '../../lib';
 
@@ -128,4 +129,36 @@ describe('#resolveVariables', function() {
       }
     ]);
   });
+
+
+  it('should resolve formal parameters of function definition', async function() {
+
+    // given
+    const parsed = await parse(FunctionDefinitionDmn);
+    const element = findElementById(parsed, 'Bkm_1'),
+          fn = element.get('encapsulatedLogic'),
+          parameters = fn.get('formalParameter'),
+          functionBody = fn.get('body');
+
+    // when
+    const variables = resolveVariables(functionBody);
+
+    // then
+    expect(variables).to.eql([
+      {
+        name: 'noType',
+        origin: parameters[0]
+      },
+      {
+        name: 'string',
+        detail: 'string',
+        origin: parameters[1]
+      },
+      {
+        name: 'num',
+        detail: 'number',
+        origin: parameters[2]
+      }
+    ]);
+  });
 });