fix(parse-dsl): fix issue with infinite loops triggered when parsing …

…some models (#76)

* fix: adding test for parseDSL with spaces
* fix: handle a case of an infinite loop while parsing the grammar

Co-authored-by: Raghd Hamzeh <raghd.hamzeh@auth0.com>

src/openfga.ne

@@ -1,11 +1,12 @@
 @preprocessor typescript
 
-types           -> (_newline):* (type (relations (define):+):*):* {%
+types           ->   (_newline):* (type (_relations (_multiline_comment define):+):*):* {%
     // @ts-ignore
     (data) => {
         // @ts-ignore
         const types = data[1].map((datum) => {
-            const relations = datum[1][0] ? datum[1][0][1].flat() : [];
+            // @ts-ignore
+            const relations = (datum[1] && datum[1][0] && datum[1][0][1].map(innerDatum => innerDatum[1])) || [];
 
             return { ...datum[0], relations }
         })
@@ -18,35 +19,39 @@ types           -> (_newline):* (type (relations (define):+):*):* {%
     }
 %}
 
-type            -> _multiline_comment _type _naming (_newline):+ {%
+type            ->  _multiline_comment _type _naming (_newline):+{%
     data => ({ comment: data[0], type: data[2] })
 %}
-relations       -> _multiline_comment _relations {%
-    data => data[1]
+relations       ->  _relations {%
+    data => data[0]
 %}
-define          -> (_newline):+ _multiline_comment define_initial (_relation_types):? _as (define_base | define_or | define_and | define_but_not) (_newline):* {%
+define          ->  _newline define_initial (_spacing | _relation_types) _as _spacing (define_base | define_or | define_and | define_but_not) (_newline):*  {%
     (data, _location, reject) => {
-        const relation = data[2];
-
+        const relation = data[1];
+        // Not supported yet
+        const comment = "";
         const def = data[5][0];
         const definition = def.type ? def :
             {
                 type: 'single',
                 targets: [def]
             }
-        const allowedTypes = data[3] ? data[3][0] : []
+        let allowedTypes = data[2] ? data[2][0] : [];
+        if (allowedTypes.length && typeof allowedTypes[0] !== "string") {
+          allowedTypes = [];
+        }
 
-        return { comment: data[1], allowedTypes, relation, definition };
+        return { comment, allowedTypes, relation, definition };
     }
 %}
 
 define_initial      -> _define _naming {%
 	data => data[1]
 %}
 
-define_base  -> _optional_space (_naming | from_phrase) _optional_space {%
+define_base  ->  (_naming | from_phrase) {%
     data => {
-		const entry = data[1][0];
+		const entry = data[0][0];
 		let target, rewrite, from
 		if (typeof entry === "string") {
 			if (entry === "self") {
@@ -72,8 +77,8 @@ define_and      -> define_base (_spacing _and _spacing define_base):+ {%
     // @ts-ignore
     data => ({ targets: [data[0], ...data[1].map((datum) => datum[3])], type: "intersection" })
 %}
-define_but_not  -> define_base _but_not define_base {%
-    data => ({ base: data[0], diff: data[2], type: "exclusion" })
+define_but_not  -> define_base _spacing _but_not _spacing define_base {%
+    data => ({ base: data[0], diff: data[4], type: "exclusion" })
 %}
 from_phrase -> _naming _spacing _from _spacing _naming {%
     data => ({ target: data[0], from: data[4] })
@@ -82,15 +87,15 @@ from_phrase -> _naming _spacing _from _spacing _naming {%
 _multiline_comment        -> (_comment):* {%
     data => data.flat(3).join('\n')
 %}
-_comment        -> " ":* "#" _spacing _naming (_spacing _word):*  _newline {%
+_comment        -> (_newline):?  _optional_space "#" _optional_space _word (_spacing _word):*  (_newline):?  {%
     data => data.flat(3).join('').trim().substring(1).trim()
 %}
 _word           -> ([a-z] | [A-Z] | [0-9] |  "_" |  "-" | "," | "&" | "+" | "/" | "$" ):+ _optional_space {%
     data => data.flat(3).join('').trim()
 %}
 
-_relation_types -> ":" _optional_space "[" _array_of_types "]" _spacing {%
-    data => data[3]
+_relation_types -> _optional_space ":" _optional_space "[" _array_of_types "]" _spacing {%
+    data => data[4]
 %}
 
 _array_of_types -> ("$"):? ([a-zA-Z0-9_#\-,\s]):+ {%
@@ -105,10 +110,10 @@ _but_not        -> "but not"
 
 _self           -> "self"
 _define          -> "    define" _spacing
-_relations      -> "  relations" _optional_space
+_relations      -> "  relations" (_newline):*
 _type           -> "type" _spacing
 _no_relations   -> "none" (_newline):*
-_naming         -> (("$"):? ( [a-z] | [A-Z] | [0-9] |  "_" |  "-" ):+) _optional_space {%
+_naming         -> (("$"):? ( [a-z] | [A-Z] | [0-9] |  "_" |  "-" ):+) {%
     data => data.flat(3).join('').trim()
 %}
 _optional_space -> " ":*

src/parse-dsl.ts

@@ -44,10 +44,19 @@ export interface ParserResult {
   types: TypeDefParserResult[];
 }
 
-export const parseDSL = (code: string): ParserResult => {
+export const innerParseDSL = (code: string): ParserResult[] => {
   const parser = new Parser(Grammar.fromCompiled(grammar));
-  parser.feed(code.trim() + "\n");
-  return parser.results[0] || [];
+  const cleanedCode =
+    code
+      .split("\n")
+      .map((line) => line.trimEnd())
+      .join("\n") + "\n";
+  parser.feed(cleanedCode);
+  return parser.results;
+};
+
+export const parseDSL = (code: string): ParserResult => {
+  return innerParseDSL(code)[0] || [];
 };
 
 // The TransformedType allows us to quickly access the various relations unique by

tests/__snapshots__/index.test.ts.snap

@@ -28,7 +28,7 @@ exports[`apiSyntaxToFriendlySyntax should correctly read from \`or\` definition
 "
 `;
 
-exports[`apiSyntaxToFriendlySyntax should read a complex definition 1`] = `
+exports[`apiSyntaxToFriendlySyntax should read a complex definition 4 1`] = `
 "type folder
   relations
     define deleter as self
@@ -212,7 +212,7 @@ exports[`friendlySyntaxToApiSyntax() should correctly read from \`or\` definitio
 }
 `;
 
-exports[`friendlySyntaxToApiSyntax() should read a complex definition 1`] = `
+exports[`friendlySyntaxToApiSyntax() should read a complex definition 1 1`] = `
 {
   "schema_version": "1.0",
   "type_definitions": [
@@ -327,7 +327,7 @@ exports[`friendlySyntaxToApiSyntax() should read a complex definition 1`] = `
 }
 `;
 
-exports[`friendlySyntaxToApiSyntax() should read a complex definition 2`] = `
+exports[`friendlySyntaxToApiSyntax() should read a complex definition 2 1`] = `
 {
   "schema_version": "1.0",
   "type_definitions": [
@@ -415,7 +415,7 @@ exports[`friendlySyntaxToApiSyntax() should read a complex definition 2`] = `
 }
 `;
 
-exports[`friendlySyntaxToApiSyntax() should read a complex definition 3`] = `
+exports[`friendlySyntaxToApiSyntax() should read a complex definition 3 1`] = `
 {
   "schema_version": "1.0",
   "type_definitions": [