Fix property between Role and Person for contributors (#52)

It should be:

```
{
    "@context": "https://doi.org/10.5063/schema/codemeta-2.0",
    "type": "SoftwareSourceCode",
    "contributor": [
        {
            "type": "schema:Role",
            "schema:contributor": {
                "type": "Person",
                "givenName": "Jane"
            },
        }
    ]
}
```

instead of:

```
{
    "@context": "https://doi.org/10.5063/schema/codemeta-2.0",
    "type": "SoftwareSourceCode",
    "contributor": [
        {
            "type": "schema:Role",
            "schema:author": {
                "type": "Person",
                "givenName": "Jane"
            },
        }
    ]
}
```

Author: progval

cypress/integration/persons.js

@@ -985,3 +985,61 @@ describe('Contributors', function () {
         cy.get('#contributor_2_givenName').should('have.value', 'Joe');
     });
 });
+
+describe('One contributor with a role', function () {
+    it('can be exported in both codemeta v2.0 and v3.0 versions', function () {
+        cy.get('#name').type('My Test Software');
+
+        cy.get('#contributor_add').click();
+        cy.get('#contributor_1_givenName').type('Jane');
+
+        cy.get('#contributor_1_role_add').click();
+        cy.get('#contributor_1_roleName_0').type('Developer');
+        cy.get('#contributor_1_startDate_0').type('2024-03-04');
+        cy.get('#contributor_1_endDate_0').type('2024-04-03');
+
+        cy.get('#generateCodemetaV2').click();
+        cy.get('#codemetaText').then((elem) => JSON.parse(elem.text()))
+            .should('deep.equal', {
+                "@context": "https://doi.org/10.5063/schema/codemeta-2.0",
+                "type": "SoftwareSourceCode",
+                "name": "My Test Software",
+                "contributor": [
+                    {
+                        "id": "_:contributor_1",
+                        "type": "Person",
+                        "givenName": "Jane"
+                    },
+                    {
+                        "type": "schema:Role",
+                        "contributor": "_:contributor_1",
+                        "schema:roleName": "Developer",
+                        "schema:startDate": "2024-03-04",
+                        "schema:endDate": "2024-04-03"
+                    }
+                ]
+            });
+
+        cy.get('#generateCodemetaV3').click();
+        cy.get('#codemetaText').then((elem) => JSON.parse(elem.text()))
+            .should('deep.equal', {
+                "@context": "https://w3id.org/codemeta/3.0",
+                "type": "SoftwareSourceCode",
+                "name": "My Test Software",
+                "contributor": [
+                    {
+                        "id": "_:contributor_1",
+                        "type": "Person",
+                        "givenName": "Jane"
+                    },
+                    {
+                        "type": "Role",
+                        "contributor": "_:contributor_1",
+                        "roleName": "Developer",
+                        "startDate": "2024-03-04",
+                        "endDate": "2024-04-03"
+                    }
+                ]
+            });
+    });
+});

js/codemeta_generation.js

@@ -181,26 +181,26 @@ function generateRole(id) {
     return doc;
 }
 
-function generateRoles(idPrefix, person) {
+function generateRoles(property, idPrefix, person) {
     const roles = [];
     const roleNodes = document.querySelectorAll(`ul[id^=${idPrefix}_role_`);
     roleNodes.forEach(roleNode => {
         const role = generateRole(roleNode.id);
-        role["schema:author"] = getDocumentId(person); // Prefix with "schema:" to prevent it from expanding into a list
+        role[`schema:${property}`] = getDocumentId(person); // Prefix with "schema:" to prevent it from expanding into a list
         roles.push(role);
     });
     return roles;
 }
 
-function generatePersons(prefix) {
+function generatePersons(property) {
     var persons = [];
-    var nbPersons = getNbPersons(prefix);
+    var nbPersons = getNbPersons(property);
 
     for (let personId = 1; personId <= nbPersons; personId++) {
-        const idPrefix = `${prefix}_${personId}`;
+        const idPrefix = `${property}_${personId}`;
         const person = generatePerson(idPrefix);
         persons.push(person);
-        const roles = generateRoles(idPrefix, person);
+        const roles = generateRoles(property, idPrefix, person);
         if (roles.length > 0) {
             persons = persons.concat(roles);
         }