test: replacing one triple with many

Author: tpluscode

packages/processor/index.ts

@@ -308,27 +308,27 @@ export default abstract class ProcessorImpl<F extends DataFactory = DataFactory>
     let currentBgp: sparqljs.BgpPattern | undefined
 
     return triples.reduce((patterns: sparqljs.Pattern[], triple) => {
-      const processedTriple = this.processTriple(triple)
-      if ('subject' in processedTriple) {
-        if (!currentBgp) {
-          currentBgp = { type: 'bgp', triples: [processedTriple] }
-          return [...patterns, currentBgp]
-        }
-
-        currentBgp.triples.push(processedTriple)
-        return patterns
-      }
+      const result = this.processTriple(triple)
+      const processedTriples = Array.isArray(result) ? result : [result]
+
+      return processedTriples.reduce((patterns: sparqljs.Pattern[], processedTriple) => {
+        if ('subject' in processedTriple) {
+          if (!currentBgp) {
+            currentBgp = { type: 'bgp', triples: [processedTriple] }
+            return [...patterns, currentBgp]
+          }
 
-      currentBgp = undefined
-      if (Array.isArray(processedTriple)) {
-        return [...patterns, ...processedTriple]
-      }
+          currentBgp.triples.push(processedTriple)
+          return patterns
+        }
 
-      return [...patterns, processedTriple]
+        currentBgp = undefined
+        return [...patterns, processedTriple]
+      }, patterns)
     }, [])
   }
 
-  processTriple(triple: sparqljs.Triple): sparqljs.Triple | sparqljs.Pattern | sparqljs.Pattern[] {
+  processTriple(triple: sparqljs.Triple): sparqljs.Triple | sparqljs.Triple[] | sparqljs.Pattern | sparqljs.Pattern[] {
     return {
       subject: this.processTerm(triple.subject),
       predicate: match(triple.predicate)

packages/processor/test/index.test.ts

@@ -16,7 +16,8 @@ describe('@hydrofoil/sparql-processor', function () {
         const name = path.basename(file)
 
         it(`does not modify the query (${name})`, function () {
-          const processor = new (class extends QueryProcessor {})(rdf)
+          const processor = new (class extends QueryProcessor {
+          })(rdf)
 
           const processed = processor.process(loadQuery(name))
 
@@ -27,33 +28,60 @@ describe('@hydrofoil/sparql-processor', function () {
     })
 
     context('replacing triples with other patterns', function () {
-      class FullTextSearchProcessor extends QueryProcessor {
-        override processTriple(triple: Triple) {
-          if ('termType' in triple.predicate && triple.predicate.value === 'http://example.org/fullTextSearch') {
-            return <FilterPattern>{
-              type: 'filter',
-              expression: {
-                type: 'operation',
-                operator: 'regex',
-                args: [
-                  triple.subject,
-                  triple.object,
-                ],
-              },
+      context('magic property', function () {
+        class FullTextSearchProcessor extends QueryProcessor {
+          override processTriple(triple: Triple) {
+            if ('termType' in triple.predicate && triple.predicate.value === 'http://example.org/fullTextSearch') {
+              return <FilterPattern>{
+                type: 'filter',
+                expression: {
+                  type: 'operation',
+                  operator: 'regex',
+                  args: [
+                    triple.subject,
+                    triple.object,
+                  ],
+                },
+              }
             }
+            return super.processTriple(triple)
           }
-          return super.processTriple(triple)
         }
-      }
 
-      it('replaces triples with fullTextSearch predicate', function () {
-        const processor = new FullTextSearchProcessor(rdf)
+        it('replaces triples with fullTextSearch predicate', function () {
+          const processor = new FullTextSearchProcessor(rdf)
 
-        const query = loadQuery('triple-patterns/magic-property.rq')
-        const processed = processor.process(query)
+          const query = loadQuery('triple-patterns/magic-property.rq')
+          const processed = processor.process(query)
 
-        expect(stringifyQuery(processed))
-          .to.deep.equal(stringifyQuery(loadQuery('triple-patterns/magic-property.expected.rq')))
+          expect(stringifyQuery(processed))
+            .to.deep.equal(stringifyQuery(loadQuery('triple-patterns/magic-property.expected.rq')))
+        })
+      })
+
+      context('multiple resulting patterns', function () {
+        class FullTextSearchProcessor extends QueryProcessor {
+          override processTriple(triple: Triple) {
+            if ('type' in triple.predicate && triple.predicate.pathType === '/') {
+              return triple.predicate.items.map((predicate, index, array): Triple => {
+                const subject = index === 0 ? triple.subject : this.factory.variable(`v${index - 1}`)
+                const object = index === array.length - 1 ? triple.object : this.factory.variable(`v${index}`)
+                return { subject, predicate, object }
+              })
+            }
+            return super.processTriple(triple)
+          }
+        }
+
+        it('replaces one triples with multiple', function () {
+          const processor = new FullTextSearchProcessor(rdf)
+
+          const query = loadQuery('triple-patterns/sequence.rq')
+          const processed = processor.process(query)
+
+          expect(stringifyQuery(processed))
+            .to.deep.equal(stringifyQuery(loadQuery('triple-patterns/sequence.expected.rq')))
+        })
       })
     })
   })

packages/processor/test/queries/triple-patterns/sequence.expected.rq

@@ -0,0 +1,9 @@
+PREFIX ex: <http://example.org/>
+PREFIX schema: <http://schema.org/>
+
+SELECT * {
+    ?s a schema:Person .
+    ?s schema:knows ?v0 .
+    ?v0 schema:knows ?friend  .
+    ?s schema:name ?name .
+}

packages/processor/test/queries/triple-patterns/sequence.rq

@@ -0,0 +1,8 @@
+PREFIX ex: <http://example.org/>
+PREFIX schema: <http://schema.org/>
+
+SELECT * {
+    ?s a schema:Person .
+    ?s schema:knows/schema:knows ?friend  .
+    ?s schema:name ?name .
+}