From f568886d5dceacf485deffa1244fae515318868c Mon Sep 17 00:00:00 2001
From: Juan Cruz Viotti <jv@jviotti.com>
Date: Mon, 3 Aug 2026 09:28:18 -0300
Subject: [PATCH] Add some more JSON-LD related custom linter rules

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>
---
 jsonschema.json                           |   5 +
 rules/jsonld-bare-override.json           |   6 +
 rules/jsonld-constants-iri-literal.json   |  60 ++++++++++
 rules/jsonld-constants-lexical.json       | 133 ++++++++++++++++++++++
 rules/jsonld-constants-reserved-type.json |  42 +++++++
 rules/jsonld-datatype-reserved.json       |  15 +++
 rules/jsonld-unmarked-null.json           |  16 +++
 rules/jsonld-value-rdf-type.json          |  12 ++
 8 files changed, 289 insertions(+)
 create mode 100644 rules/jsonld-constants-iri-literal.json
 create mode 100644 rules/jsonld-constants-lexical.json
 create mode 100644 rules/jsonld-constants-reserved-type.json
 create mode 100644 rules/jsonld-datatype-reserved.json
 create mode 100644 rules/jsonld-value-rdf-type.json

diff --git a/jsonschema.json b/jsonschema.json
index 29aeb15a..0a3d2a78 100644
--- a/jsonschema.json
+++ b/jsonschema.json
@@ -13,7 +13,12 @@
       "./rules/dialect.json",
       "./rules/identifiers.json",
       "./rules/jsonld-bare-override.json",
+      "./rules/jsonld-constants-iri-literal.json",
+      "./rules/jsonld-constants-lexical.json",
+      "./rules/jsonld-constants-reserved-type.json",
+      "./rules/jsonld-datatype-reserved.json",
       "./rules/jsonld-unmarked-null.json",
+      "./rules/jsonld-value-rdf-type.json",
       "./rules/license.json",
       "./rules/links.json",
       "./rules/single-line-text.json",
diff --git a/rules/jsonld-bare-override.json b/rules/jsonld-bare-override.json
index 6493fc3d..57b971c7 100644
--- a/rules/jsonld-bare-override.json
+++ b/rules/jsonld-bare-override.json
@@ -36,6 +36,12 @@
       },
       {
         "required": [ "x-jsonld-self" ]
+      },
+      {
+        "required": [ "x-jsonld-value" ]
+      },
+      {
+        "required": [ "x-jsonld-constants" ]
       }
     ]
   }
diff --git a/rules/jsonld-constants-iri-literal.json b/rules/jsonld-constants-iri-literal.json
new file mode 100644
index 00000000..c3c7194b
--- /dev/null
+++ b/rules/jsonld-constants-iri-literal.json
@@ -0,0 +1,60 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "std/jsonld_constants_iri_literal",
+  "description": "A bare string in a constants fragment is always a string literal, so a string that looks like an IRI is almost certainly a node reference missing its id member",
+  "properties": {
+    "x-jsonld-constants": {
+      "additionalProperties": {
+        "allOf": [
+          {
+            "$ref": "#/$defs/term"
+          },
+          {
+            "if": {
+              "type": "array"
+            },
+            "then": {
+              "items": {
+                "$ref": "#/$defs/term"
+              }
+            }
+          }
+        ]
+      }
+    }
+  },
+  "$defs": {
+    "term": {
+      "allOf": [
+        {
+          "not": {
+            "type": "string",
+            "pattern": "^([A-Za-z][A-Za-z0-9+.-]*://|urn:|mailto:|did:|tag:)"
+          }
+        },
+        {
+          "not": {
+            "type": "object",
+            "not": {
+              "anyOf": [
+                {
+                  "required": [ "@type" ]
+                },
+                {
+                  "required": [ "@language" ]
+                }
+              ]
+            },
+            "required": [ "@value" ],
+            "properties": {
+              "@value": {
+                "type": "string",
+                "pattern": "^([A-Za-z][A-Za-z0-9+.-]*://|urn:|mailto:|did:|tag:)"
+              }
+            }
+          }
+        }
+      ]
+    }
+  }
+}
diff --git a/rules/jsonld-constants-lexical.json b/rules/jsonld-constants-lexical.json
new file mode 100644
index 00000000..6d27bb91
--- /dev/null
+++ b/rules/jsonld-constants-lexical.json
@@ -0,0 +1,133 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "std/jsonld_constants_lexical",
+  "description": "A constant typed literal whose value sits outside the lexical space of its datatype converts to an ill-typed literal that RDF implementations must accept, so this is the only place to catch it",
+  "properties": {
+    "x-jsonld-constants": {
+      "additionalProperties": {
+        "allOf": [
+          {
+            "$ref": "#/$defs/term"
+          },
+          {
+            "if": {
+              "type": "array"
+            },
+            "then": {
+              "items": {
+                "$ref": "#/$defs/term"
+              }
+            }
+          }
+        ]
+      }
+    }
+  },
+  "$defs": {
+    "term": {
+      "allOf": [
+        {
+          "if": {
+            "type": "object",
+            "required": [ "@value", "@type" ],
+            "properties": {
+              "@value": {
+                "type": "number"
+              },
+              "@type": {
+                "$ref": "#/$defs/integer-datatypes"
+              }
+            }
+          },
+          "then": {
+            "properties": {
+              "@value": {
+                "multipleOf": 1
+              }
+            }
+          }
+        },
+        {
+          "if": {
+            "type": "object",
+            "required": [ "@value", "@type" ],
+            "properties": {
+              "@value": {
+                "type": "string"
+              },
+              "@type": {
+                "$ref": "#/$defs/integer-datatypes"
+              }
+            }
+          },
+          "then": {
+            "properties": {
+              "@value": {
+                "pattern": "^[+-]?[0-9]+$"
+              }
+            }
+          }
+        },
+        {
+          "if": {
+            "type": "object",
+            "required": [ "@value", "@type" ],
+            "properties": {
+              "@value": {
+                "type": "string"
+              },
+              "@type": {
+                "const": "http://www.w3.org/2001/XMLSchema#decimal"
+              }
+            }
+          },
+          "then": {
+            "properties": {
+              "@value": {
+                "pattern": "^[+-]?([0-9]+(\\.[0-9]*)?|\\.[0-9]+)$"
+              }
+            }
+          }
+        },
+        {
+          "if": {
+            "type": "object",
+            "required": [ "@value", "@type" ],
+            "properties": {
+              "@value": {
+                "type": "string"
+              },
+              "@type": {
+                "const": "http://www.w3.org/2001/XMLSchema#boolean"
+              }
+            }
+          },
+          "then": {
+            "properties": {
+              "@value": {
+                "enum": [ "true", "false", "1", "0" ]
+              }
+            }
+          }
+        }
+      ]
+    },
+    "integer-datatypes": {
+      "enum": [
+        "http://www.w3.org/2001/XMLSchema#integer",
+        "http://www.w3.org/2001/XMLSchema#long",
+        "http://www.w3.org/2001/XMLSchema#int",
+        "http://www.w3.org/2001/XMLSchema#short",
+        "http://www.w3.org/2001/XMLSchema#byte",
+        "http://www.w3.org/2001/XMLSchema#nonNegativeInteger",
+        "http://www.w3.org/2001/XMLSchema#nonPositiveInteger",
+        "http://www.w3.org/2001/XMLSchema#negativeInteger",
+        "http://www.w3.org/2001/XMLSchema#positiveInteger",
+        "http://www.w3.org/2001/XMLSchema#unsignedLong",
+        "http://www.w3.org/2001/XMLSchema#unsignedInt",
+        "http://www.w3.org/2001/XMLSchema#unsignedShort",
+        "http://www.w3.org/2001/XMLSchema#unsignedByte"
+      ]
+    }
+  }
+}
diff --git a/rules/jsonld-constants-reserved-type.json b/rules/jsonld-constants-reserved-type.json
new file mode 100644
index 00000000..196d9758
--- /dev/null
+++ b/rules/jsonld-constants-reserved-type.json
@@ -0,0 +1,42 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "std/jsonld_constants_reserved_type",
+  "description": "A langString literal requires a language tag that only the language member can provide, and a JSON literal cannot be a constant, so neither IRI is a usable value object type",
+  "properties": {
+    "x-jsonld-constants": {
+      "additionalProperties": {
+        "allOf": [
+          {
+            "$ref": "#/$defs/term"
+          },
+          {
+            "if": {
+              "type": "array"
+            },
+            "then": {
+              "items": {
+                "$ref": "#/$defs/term"
+              }
+            }
+          }
+        ]
+      }
+    }
+  },
+  "$defs": {
+    "term": {
+      "not": {
+        "type": "object",
+        "required": [ "@type" ],
+        "properties": {
+          "@type": {
+            "enum": [
+              "http://www.w3.org/1999/02/22-rdf-syntax-ns#langString",
+              "http://www.w3.org/1999/02/22-rdf-syntax-ns#JSON"
+            ]
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/rules/jsonld-datatype-reserved.json b/rules/jsonld-datatype-reserved.json
new file mode 100644
index 00000000..ecc73e1f
--- /dev/null
+++ b/rules/jsonld-datatype-reserved.json
@@ -0,0 +1,15 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "std/jsonld_datatype_reserved",
+  "description": "A langString literal requires a language tag that only x-jsonld-language can provide, and a JSON literal is declared with x-jsonld-json, so neither IRI is a usable datatype",
+  "properties": {
+    "x-jsonld-datatype": {
+      "not": {
+        "enum": [
+          "http://www.w3.org/1999/02/22-rdf-syntax-ns#langString",
+          "http://www.w3.org/1999/02/22-rdf-syntax-ns#JSON"
+        ]
+      }
+    }
+  }
+}
diff --git a/rules/jsonld-unmarked-null.json b/rules/jsonld-unmarked-null.json
index 77f1b468..119c154c 100644
--- a/rules/jsonld-unmarked-null.json
+++ b/rules/jsonld-unmarked-null.json
@@ -83,6 +83,22 @@
             "type": "null"
           }
         }
+      },
+      {
+        "required": [ "x-jsonld-value" ],
+        "properties": {
+          "x-jsonld-value": {
+            "type": "null"
+          }
+        }
+      },
+      {
+        "required": [ "x-jsonld-constants" ],
+        "properties": {
+          "x-jsonld-constants": {
+            "type": "null"
+          }
+        }
       }
     ]
   },
diff --git a/rules/jsonld-value-rdf-type.json b/rules/jsonld-value-rdf-type.json
new file mode 100644
index 00000000..a47c0f7c
--- /dev/null
+++ b/rules/jsonld-value-rdf-type.json
@@ -0,0 +1,12 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "std/jsonld_value_rdf_type",
+  "description": "The rdf:type predicate as a value predicate would mint type edges to literals, and node types are declared with x-jsonld-type",
+  "properties": {
+    "x-jsonld-value": {
+      "not": {
+        "const": "http://www.w3.org/1999/02/22-rdf-syntax-ns#type"
+      }
+    }
+  }
+}