Fix graph property empty array and safe mode.

- Fix handling of graph property with empty array.
- Fix safe mode for `@graph` use cases.
  - Check all elements of graph property with array.

Author: davidlehn

CHANGELOG.md

@@ -1,5 +1,12 @@
 # jsonld ChangeLog
 
+## 8.2.1 - 2023-xx-xx
+
+### Fixed
+- Fix handling of graph property with empty array.
+- Fix safe mode for `@graph` use cases.
+  - Check all elements of graph property with array.
+
 ## 8.2.0 - 2023-05-19
 
 ### Changed

lib/expand.js

@@ -386,6 +386,12 @@ api.expand = async ({
 
 /**
  * Drop empty object, top-level @value/@list, or object with only @id
+ *
+ * @param value Value to check.
+ * @param count Number of properties in object.
+ * @param options The expansion options.
+ *
+ * @return null if dropped, value otherwise.
  */
 function _dropUnsafeObject({
   value,
@@ -948,15 +954,17 @@ async function _expandObject({
     // index cases handled above
     if(container.includes('@graph') &&
       !container.some(key => key === '@id' || key === '@index')) {
-      // ensure expanded values are arrays
-      // ensure an array
+      // ensure expanded values are in an array
       expandedValue = _asArray(expandedValue);
-      // check if needs to be dropped
-      const count = Object.keys(expandedValue[0]).length;
-      if(!options.isFrame && _dropUnsafeObject({
-        value: expandedValue[0], count, options
-      }) === null) {
-        // skip adding and continue
+      if(!options.isFrame) {
+        // drop items if needed
+        expandedValue = expandedValue.filter(v => {
+          const count = Object.keys(v).length;
+          return _dropUnsafeObject({value: v, count, options}) !== null;
+        });
+      }
+      if(expandedValue.length === 0) {
+        // all items dropped, skip adding and continue
         continue;
       }
       // convert to graph

tests/misc.js

@@ -1885,6 +1885,72 @@ _:b0 <ex:p> "[null]"^^<http://www.w3.org/1999/02/22-rdf-syntax-ns#JSON> .
       });
     });
 
+    it('should emit for @graph with empty array (1)', async () => {
+      const input =
+{
+  "@context": {
+    "p": {
+      "@id": "urn:p",
+      "@type": "@id",
+      "@container": "@graph"
+    }
+  },
+  "@id": "urn:id",
+  "p": []
+}
+;
+      const expected = [];
+
+      await _test({
+        type: 'expand',
+        input,
+        expected,
+        eventCodeLog: [
+          'object with only @id'
+        ],
+        testNotSafe: true
+      });
+    });
+
+    it('should not emit for @graph with empty array (2)', async () => {
+      const input =
+{
+  "@context": {
+    "p": {
+      "@id": "urn:p",
+      "@type": "@id",
+      "@container": "@graph"
+    },
+    "urn:t": {
+      "@type": "@id"
+    }
+  },
+  "@id": "urn:id",
+  "urn:t": "urn:id",
+  "p": []
+}
+;
+      const expected =
+[
+  {
+    "@id": "urn:id",
+    "urn:t": [
+      {
+        "@id": "urn:id"
+      }
+    ]
+  }
+]
+;
+
+      await _test({
+        type: 'expand',
+        input,
+        expected,
+        eventCodeLog: []
+      });
+    });
+
     it('should emit for @graph with relative @id (1)', async () => {
       const input =
 {
@@ -1915,6 +1981,144 @@ _:b0 <ex:p> "[null]"^^<http://www.w3.org/1999/02/22-rdf-syntax-ns#JSON> .
 
     it('should emit for @graph with relative @id (2)', async () => {
       const input =
+{
+  "@context": {
+    "p": {
+      "@id": "urn:p",
+      "@type": "@id",
+      "@container": "@graph"
+    }
+  },
+  "@id": "urn:id",
+  "p": [
+    "rel0",
+    "rel1"
+  ]
+}
+;
+      const expected = [];
+
+      await _test({
+        type: 'expand',
+        input,
+        expected,
+        eventCodeLog: [
+          'object with only @id',
+          'object with only @id',
+          'object with only @id'
+        ],
+        testNotSafe: true
+      });
+    });
+
+    it('should emit for @graph with relative @id (3)', async () => {
+      const input =
+{
+  "@context": {
+    "p": {
+      "@id": "urn:p",
+      "@type": "@id",
+      "@container": "@graph"
+    }
+  },
+  "@id": "urn:g0",
+  "p": [
+    {
+      "@id": "urn:g1",
+      "urn:p1": "v1"
+    },
+    "rel"
+  ]
+}
+;
+      const expected =
+[
+  {
+    "@id": "urn:g0",
+    "urn:p": [
+      {
+        "@graph": [
+          {
+            "@id": "urn:g1",
+            "urn:p1": [
+              {
+                "@value": "v1"
+              }
+            ]
+          }
+        ]
+      }
+    ]
+  }
+]
+;
+
+      await _test({
+        type: 'expand',
+        input,
+        expected,
+        eventCodeLog: [
+          'object with only @id'
+        ],
+        testNotSafe: true
+      });
+    });
+
+    it('should emit for @graph with relative @id (4)', async () => {
+      const input =
+{
+  "@context": {
+    "p": {
+      "@id": "urn:p",
+      "@type": "@id",
+      "@container": "@graph"
+    }
+  },
+  "@id": "urn:g0",
+  "p": [
+    "rel",
+    {
+      "@id": "urn:g1",
+      "urn:p1": "v1"
+    }
+  ]
+}
+;
+      const expected =
+[
+  {
+    "@id": "urn:g0",
+    "urn:p": [
+      {
+        "@graph": [
+          {
+            "@id": "urn:g1",
+            "urn:p1": [
+              {
+                "@value": "v1"
+              }
+            ]
+          }
+        ]
+      }
+    ]
+  }
+]
+;
+
+      await _test({
+        type: 'expand',
+        input,
+        expected,
+        eventCodeLog: [
+          'object with only @id'
+        ],
+        testNotSafe: true
+      });
+    });
+
+    it('should emit for @graph with relative @id (5)', async () => {
+      const input =
 {
   "@context": {
     "p": {
@@ -1955,7 +2159,7 @@ _:b0 <ex:p> "[null]"^^<http://www.w3.org/1999/02/22-rdf-syntax-ns#JSON> .
       });
     });
 
-    it('should emit for @graph with relative @id (3)', async () => {
+    it('should emit for @graph with relative @id (6)', async () => {
       const input =
 {
   "@context": {
@@ -1997,7 +2201,7 @@ _:b0 <ex:p> "[null]"^^<http://www.w3.org/1999/02/22-rdf-syntax-ns#JSON> .
       });
     });
 
-    it('should emit for @graph with relative @id (4)', async () => {
+    it('should emit for @graph with relative @id (7)', async () => {
       const input =
 {
   "@context": {