fix: ParserContext type to have all methods (#57)

fix: ParserContext to have all methods

Author: nzakas

lib/index.d.ts

@@ -2729,10 +2729,13 @@ type ParseConfig = {
 } & Pick<SyntaxConfig, 'features' | 'scope'>;
 
 // https://github.com/csstree/csstree/blob/9de5189fadd6fb4e3a149eec0e80d6ed0d0541e5/lib/parser/create.js#L90
-type ParserContext = TokenStream
+type ParserContext<AvailableNodes extends CssNodeCommon = CssNode> = TokenStream
     & ParseConfig
     & { config: ParseConfig }
     & Parser
+    & {
+        [K in AvailableNodes["type"]]: (this: ParserContext, ...args: unknown[]) => Extract<AvailableNodes, { type: K }>;
+    }
     & {
         // Anything else
         [key: string]: unknown;

tests/types/types.test.ts

@@ -276,10 +276,13 @@ const customSyntax = csstree.fork({
             structure: {
                 children: [[]]
             },
-            parse: () => {
+            parse() {
+
+                const dec = this.Declaration();
+
                 return {
                     type: 'CustomNode3',
-                    value: 'hello'
+                    value: dec.property
                 };
             },
             generate(node: csstree.CssNode) {
@@ -291,10 +294,13 @@ const customSyntax = csstree.fork({
             }
         },
         CustomNode4: {
-            parse: () => {
+            parse() {
+
+                const id = this.Identifier();
+
                 return {
                     type: 'CustomNode3',
-                    value: 'hello'
+                    value: id.name
                 };
             },
         },
@@ -308,6 +314,36 @@ const customSyntax = csstree.fork({
     }
 });
 
+// Parsing with custom node types
+
+interface CustomNode extends csstree.CssNodeCommon {
+    type: 'CustomNode';
+    value: string;
+}
+
+type CustomNodes = csstree.CssNode | CustomNode;
+
+function customParseFunction(this: csstree.ParserContext<CustomNodes>, value: string) {
+
+    const node = this.CustomNode();
+    const id = this.Identifier();
+
+    return {
+        type: 'CustomNode2',
+        value: node.value
+    };
+}
+
+const partialNodeConfig: Partial<csstree.NodeSyntaxConfig> = {
+    parse(this: csstree.ParserContext<CustomNodes>, value: string) {
+        const node = this.CustomNode();
+        return {
+            type: 'CustomNode3',
+            value: node.value
+        };
+    },
+}
+
 const customAst = customSyntax.parse('.example { custom: value }');
 customSyntax.walk(customAst,
     (node) => {