feat(*): add error handling for missing/unloaded word vectors

src/as.js

@@ -186,10 +186,14 @@ as.markedUpText = function ( twps, rdd, start, end ) {
 }; // markedUpText()
 
 as.vector = function ( tokens, rdd ) {
+  if ( !rdd.wordVectors )
+    throw Error( 'wink-nlp: word vectors are not loaded, use const nlp = winkNLP( model, pipe, wordVectors ) to load.' );
+
   // Get size of a vector from word vectors
   const size = rdd.wordVectors.dimensions;
   const precision = rdd.wordVectors.precision;
   const vectors = rdd.wordVectors.vectors;
+
   // Set up a new initialized vector of `size`
   const v = new Array( size );
   v.fill( 0 );

src/wink-nlp.js

@@ -457,6 +457,9 @@ var nlp = function ( theModel, pipe, wordVectorsJSON = null ) {
   methods.as = asHelpers;
   // Vector of a token method.
   methods.vectorOf = function ( word, safe = true )  {
+    if ( !wordVectorsJSON )
+    throw Error( 'wink-nlp: word vectors are not loaded, use const nlp = winkNLP( model, pipe, wordVectors ) to load.' );
+
     const vectors = wordVectorsJSON.vectors;
     const unkVector = wordVectorsJSON.unkVector;
     const sliceUpTo = wordVectorsJSON.l2NormIndex + 1;

test/wink-nlp-specs.js

@@ -661,3 +661,15 @@ describe( 'Incorrect word vector loading', function () {
     expect( winkNLP.bind( null, model, undefined, { hello: 'world' } ) ).to.throw( /^wink-nlp: invalid word vectors format/ );
   } );
 } );
+
+describe( 'word vector methods should throw error if the vectors are not loaded', function () {
+  const myNLP = winkNLP( model );
+  const doc = myNLP.readDoc( 'this' );
+  it( 'should throw error when vectorOf() is called', function () {
+    expect( myNLP.vectorOf.bind( null, 'the' ) ).to.throw( /^wink-nlp: word vectors are not loaded/ );
+  } );
+
+  it( 'should throw error when as.vector is used', function () {
+    expect( doc.tokens().out.bind( null, its.value, as.vector ) ).to.throw( /^wink-nlp: word vectors are not loaded/ );
+  } );
+} );