🤖 Merge PR DefinitelyTyped#72789 [n3] Turn type checking functions into type predicates by @opl-

Author: opl-

types/n3/index.d.ts

@@ -373,11 +373,11 @@ export interface StoreOptions {
 }
 
 export namespace Util {
-    function isNamedNode(value: RDF.Term | null): boolean;
-    function isBlankNode(value: RDF.Term | null): boolean;
-    function isLiteral(value: RDF.Term | null): boolean;
-    function isVariable(value: RDF.Term | null): boolean;
-    function isDefaultGraph(value: RDF.Term | null): boolean;
+    function isNamedNode(value: RDF.Term | null): value is RDF.NamedNode;
+    function isBlankNode(value: RDF.Term | null): value is RDF.BlankNode;
+    function isLiteral(value: RDF.Term | null): value is RDF.Literal;
+    function isVariable(value: RDF.Term | null): value is RDF.Variable;
+    function isDefaultGraph(value: RDF.Term | null): value is RDF.DefaultGraph;
     function inDefaultGraph(value: RDF.Quad): boolean;
     function prefix(iri: RDF.NamedNode | string, factory?: RDF.DataFactory): PrefixedToIri;
     function prefixes(

types/n3/n3-tests.ts

@@ -434,6 +434,23 @@ function test_doc_utility() {
     const namedNode1: RDF.NamedNode = N3Util.prefix("http://www.w3.org/2000/01/rdf-schema#")("label");
     const namedNode2: RDF.NamedNode = N3Util.prefixes(prefixes)("rdfs")("label");
     const namedNode3: N3.NamedNode = N3Util.prefixes(prefixes)("rdfs")("label");
+
+    const term = N3.DataFactory.literal("Mickey Mouse") as RDF.Term;
+    if (N3Util.isNamedNode(term)) {
+        const namedNodeTerm: RDF.NamedNode = term;
+    }
+    if (N3Util.isBlankNode(term)) {
+        const blankNodeTerm: RDF.BlankNode = term;
+    }
+    if (N3Util.isLiteral(term)) {
+        const literalTerm: RDF.Literal = term;
+    }
+    if (N3Util.isVariable(term)) {
+        const variableTerm: RDF.Variable = term;
+    }
+    if (N3Util.isDefaultGraph(term)) {
+        const defaultGraphTerm: RDF.DefaultGraph = term;
+    }
 }
 
 function test_parser_options() {