WIP, add autogenerated tests against upstream

package.json

@@ -4,7 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "tape tests/**/* | tap-difflet"
   },
   "repository": {
     "type": "git",
@@ -32,11 +32,14 @@
     "map-obj": "^5.0.0",
     "match-value": "^1.1.0",
     "split-filter": "^1.1.3",
+    "tap-difflet": "^0.7.2",
+    "tape": "^5.5.0",
     "tree-sitter-javascript": "^0.19.0",
     "tree-sitter-nix": "cstrahan/tree-sitter-nix"
   },
   "devDependencies": {
     "@joepie91/eslint-config": "^1.1.0",
-    "eslint": "^8.8.0"
+    "eslint": "^8.8.0",
+    "tape-catch": "^1.0.6"
   }
 }

run.js

@@ -3,44 +3,11 @@
 const fs = require("fs");
 const assert = require("assert");
 
-const transpile = require("./src/transpile");
-const measureTime = require("./src/astformer/util/measure-time");
+const evaluate = require("./src/evaluate");
 
 assert(process.argv[2] != null);
 
 const nixFilePath = process.argv[2];
 const nixFile = fs.readFileSync(nixFilePath, "utf8");
 
-let transpiled = transpile(nixFile);
-
-const api = {
-	builtins: {},
-	$$jsNix$memoize: function (func) {
-		let isCalled = false;
-		let storedResult;
-
-		return function (arg) {
-			if (isCalled === false) {
-				storedResult = func(arg);
-				isCalled = true;
-			}
-
-			return storedResult;
-		};
-	}
-};
-
-// TODO: Switch to Node `vm` API instead, and check whether there's a polyfill for it for non-Node environments, build a custom one if not
-const context = { module: {}, exports: {} };
-context.module.exports = exports;
-
-new Function("module", transpiled)(context.module);
-
-console.log("-- EVALUATION RESULT:");
-
-// Warm-up for hot VM performance testing
-// for (let i = 0; i < 10000; i++) {
-// 	context.module.exports(api);
-// }
-
-console.log(measureTime(() => context.module.exports(api)));
+console.log(evaluate(nixFile));

src/astformer/index.js

@@ -196,7 +196,7 @@ module.exports = function optimizeTree(ast, optimizers) {
 					debuggers[debuggerName](`Node of type '${typeOf(node)}' replaced by node of type '${typeOf(result)}'`);
 
 					if (iterations >= EVALUATION_LIMIT) {
-						throw new Error(`Exceeded evaluation limit in optimizer ${debuggerName}; aborting optimization. If you are a user of raqb, please report this as a bug. If you are writing an optimizer, make sure that your optimizer eventually stabilizes on a terminal condition (ie. NoChange)!`);
+						throw new Error(`Exceeded evaluation limit in optimizer ${debuggerName}; aborting optimization. If you are a user of this software, please report this as a bug. If you are a developer writing an optimizer, make sure that your optimizer eventually stabilizes on a terminal condition (ie. NoChange)!`);
 					} else {
 						return handleASTNode(result, iterations + 1, path, initialStateLog, context);
 					}

src/evaluate.js

@@ -0,0 +1,45 @@
+"use strict";
+
+const measureTime = require("./astformer/util/measure-time");
+const transpile = require("./transpile");
+
+module.exports = function evaluate(nixCode) {
+	let transpiled = transpile(nixCode);
+
+	const api = {
+		builtins: {},
+		$$jsNix$memoize: function (func) {
+			let isCalled = false;
+			let storedResult;
+
+			return function (arg) {
+				if (isCalled === false) {
+					storedResult = func(arg);
+					isCalled = true;
+				}
+
+				return storedResult;
+			};
+		}
+	};
+
+	// TODO: Switch to Node `vm` API instead, and check whether there's a polyfill for it for non-Node environments, build a custom one if not
+	const context = { module: {}, exports: {} };
+	context.module.exports = exports;
+
+	new Function("module", transpiled)(context.module);
+
+	// Warm-up for hot VM performance testing
+	// for (let i = 0; i < 10000; i++) {
+	// 	context.module.exports(api);
+	// }
+
+	let result = measureTime(() => context.module.exports(api));
+
+	if (process.env.DEBUG_NIX) {
+		console.log("-- EVALUATION RESULT:");
+		console.log(result);
+	}
+
+	return result;
+};

src/transformers/literals.js

@@ -7,5 +7,13 @@ module.exports = {
 	visitors: {
 		NixIntegerLiteral: (node) => types.numericLiteral(parseInt(node.value)),
 		NixFloatLiteral: (node) => types.numericLiteral(parseFloat(node.value)),
+		NixStringLiteral: (node) => {
+			if (node.parts.length === 1 && node.parts[0].type === "NixInterpolationLiteral") {
+				// Fast case; just a simple, non-interpolated string literal
+				return types.stringLiteral(node.parts[0].value);
+			} else {
+				throw new Error(`Unimplemented: string interpolation is not supported yet`);
+			}
+		}
 	}
 };

tests/upstream-nix.js

@@ -0,0 +1,40 @@
+"use strict";
+
+const tape = require("tape-catch");
+const fs = require("fs");
+const path = require("path");
+const evaluate = require("../src/evaluate");
+
+const NIX_SOURCE_REPO = process.env.NIX_SOURCE_REPO;
+
+if (NIX_SOURCE_REPO == null) {
+	throw new Error(`To run the upstream Nix language tests, you must specify a NIX_SOURCE_REPO environment variable, that points at the root of a local checkout of the Git repository for Nix`);
+}
+
+const testsPath = path.join(NIX_SOURCE_REPO, "tests/lang");
+
+let tests = fs.readdirSync(testsPath)
+	.filter((entry) => entry.endsWith(".exp"))
+	.map((entry) => entry.replace(/\.exp$/, ""));
+
+for (let test of tests) {
+	try {
+		let expression = fs.readFileSync(path.join(testsPath, `${test}.nix`), "utf8");
+		let expectedResult = fs.readFileSync(path.join(testsPath, `${test}.exp`), "utf8").replace(/\n$/, "");
+
+		tape(`Nix upstream language tests - ${test}`, (test) => {
+			test.plan(1);
+
+			let result = evaluate(expression).value.toString();
+
+			test.equals(expectedResult, result);
+		});
+	} catch (error) {
+		// FIXME: This would currently cause ENOENTs during evaluation (eg. reading a file from Nix itself) to be ignored
+		if (error.code === "ENOENT") {
+			// skip
+		} else {
+			throw error;
+		}
+	}
+}