improve coverage

test/src/ll1/UnexpectedEndOfFileError.js

@@ -0,0 +1,86 @@
+import test from 'ava' ;
+
+import { iter , map , enumerate , list , range , nrepeat } from '@aureooms/js-itertools' ;
+import tape , { asyncIterableToArray , asyncIterableMap } from '@aureooms/js-tape' ;
+import { grammar , ast , ll1 , error } from '../../../src' ;
+
+const {
+	UnexpectedEndOfFileError ,
+} = error ;
+
+async function throws ( t , G , n ) {
+
+	t.true(ll1.is(G));
+
+	const parser = ll1.from(G);
+
+	const tokens = tape.fromIterable(
+		map(
+			i => ({
+				"type" : "leaf" ,
+				"terminal" : "x" ,
+				"buffer" : "x" ,
+				"position" : i ,
+			}) ,
+			range(2*n+1)
+		)
+	) ;
+
+	const tree = await parser.parse(tokens);
+
+	const flattened = ast.flatten( tree ) ;
+
+	const chunks = asyncIterableMap( leaf => leaf.buffer , flattened ) ;
+
+	const output = tape.fromAsyncIterable( chunks ) ;
+
+	// THIS DOES NOT WORK
+	// await t.throws( () => tape.toString( output ) , new RegExp( `at ${n+1} \\(y\\)` ) ) ;
+
+	return tape.toString( output )
+		.then( string => t.fail() )
+		.catch( error => {
+			t.true(error instanceof UnexpectedEndOfFileError) ;
+			t.true(/expected one of \["x"\]/.test(error.message));
+		} ) ;
+
+}
+
+throws.title = ( grammar , G , n ) => `Unexpected end of file error (${grammar}, ${n}).` ;
+
+const G1 = grammar.from( {
+	"start" : "letters" ,
+	"eof" : "$" ,
+	"productions" : {
+		"letters" : {
+			"add" : [ "=x" , "=x" , "&letters" ] ,
+			"end" : [ ] ,
+		} ,
+	} ,
+} ) ;
+
+const G2 = grammar.from( {
+	"start" : "letters" ,
+	"eof" : "$" ,
+	"productions" : {
+		"letters" : {
+			"add" : [ "&letter" , "&letter" , "&letters" ] ,
+			"end" : [ ] ,
+		} ,
+		"letter" : {
+			"x" : [ "=x" ] ,
+		} ,
+	} ,
+} ) ;
+
+test( throws , G1 , 0 ) ;
+test( throws , G1 , 2 ) ;
+test( throws , G1 , 10 ) ;
+test( throws , G1 , 100 ) ;
+test( throws , G1 , 666 ) ;
+
+test( throws , G2 , 0 ) ;
+test( throws , G2 , 2 ) ;
+test( throws , G2 , 10 ) ;
+test( throws , G2 , 100 ) ;
+test( throws , G2 , 666 ) ;