feat: make @agoric/eslint-plugin deal with assert.fail as throw

package.json

@@ -5,6 +5,7 @@
   "useWorkspaces": true,
   "workspaces": [
     "golang/cosmos",
+    "packages/eslint-plugin",
     "packages/eslint-config",
     "packages/assert",
     "packages/base64",

packages/eslint-config/eslint-config.json

@@ -2,7 +2,8 @@
   "extends": [
     "airbnb-base",
     "plugin:prettier/recommended",
-    "plugin:jsdoc/recommended"
+    "plugin:jsdoc/recommended",
+    "plugin:@agoric/recommended"
   ],
   "parser": "@typescript-eslint/parser",
   "env": {

packages/eslint-config/package.json

@@ -28,6 +28,7 @@
     "singleQuote": true
   },
   "devDependencies": {
+    "@agoric/eslint-plugin": "^0.0.0",
     "@typescript-eslint/parser": "^4.1.0",
     "eslint": "^6.8.0",
     "eslint-config-airbnb-base": "^14.0.0",

packages/eslint-plugin/README.md

@@ -0,0 +1,51 @@
+# eslint-plugin-agoric
+
+Agoric-specific plugin
+
+## Installation
+
+You'll first need to install [ESLint](http://eslint.org):
+
+```
+$ npm i eslint --save-dev
+```
+
+Next, install `eslint-plugin-agoric`:
+
+```
+$ npm install eslint-plugin-agoric --save-dev
+```
+
+**Note:** If you installed ESLint globally (using the `-g` flag) then you must also install `eslint-plugin-agoric` globally.
+
+## Usage
+
+Add `agoric` to the plugins section of your `.eslintrc` configuration file. You can omit the `eslint-plugin-` prefix:
+
+```json
+{
+    "plugins": [
+        "agoric"
+    ]
+}
+```
+
+
+Then configure the rules you want to use under the rules section.
+
+```json
+{
+    "rules": {
+        "agoric/rule-name": 2
+    }
+}
+```
+
+## Supported Rules
+
+* Fill in provided rules here
+
+
+
+
+

packages/eslint-plugin/lib/configs/recommended.js

@@ -0,0 +1,6 @@
+module.exports = {
+  plugins: ["@agoric"],
+  rules: {
+    "@agoric/assert-fail-as-throw": 2
+  },
+};

packages/eslint-plugin/lib/index.js

@@ -0,0 +1,20 @@
+/**
+ * @fileoverview Agoric-specific plugin
+ * @author Agoric
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+var requireIndex = require("requireindex");
+
+//------------------------------------------------------------------------------
+// Plugin Definition
+//------------------------------------------------------------------------------
+
+
+// import all rules in lib/rules
+module.exports.rules = requireIndex(__dirname + "/rules");
+module.exports.configs = requireIndex(__dirname + "/configs");

packages/eslint-plugin/lib/rules/assert-fail-as-throw.js

@@ -0,0 +1,167 @@
+/**
+ * @author Toru Nagashima
+ * See LICENSE file in root directory for full license.
+ * 
+ * Modified by Michael FIG <mfig@agoric.com> for Agoric's assert.fail.
+ * (This file used to be github.com/mysticatea/eslint-plugin-node/.../process-exit-as-throw.js.)
+ */
+"use strict"
+
+const CodePathAnalyzer = safeRequire(
+    "eslint/lib/linter/code-path-analysis/code-path-analyzer",
+    "eslint/lib/code-path-analysis/code-path-analyzer"
+)
+const CodePathSegment = safeRequire(
+    "eslint/lib/linter/code-path-analysis/code-path-segment",
+    "eslint/lib/code-path-analysis/code-path-segment"
+)
+const CodePath = safeRequire(
+    "eslint/lib/linter/code-path-analysis/code-path",
+    "eslint/lib/code-path-analysis/code-path"
+)
+
+const originalLeaveNode =
+    CodePathAnalyzer && CodePathAnalyzer.prototype.leaveNode
+
+/**
+ * Imports a specific module.
+ * @param {...string} moduleNames - module names to import.
+ * @returns {object|null} The imported object, or null.
+ */
+function safeRequire(...moduleNames) {
+    for (const moduleName of moduleNames) {
+        try {
+            return require(moduleName)
+        } catch (_err) {
+            // Ignore.
+        }
+    }
+    return null
+}
+
+/* istanbul ignore next */
+/**
+ * Copied from https://github.com/eslint/eslint/blob/16fad5880bb70e9dddbeab8ed0f425ae51f5841f/lib/code-path-analysis/code-path-analyzer.js#L137
+ *
+ * @param {CodePathAnalyzer} analyzer - The instance.
+ * @param {ASTNode} node - The current AST node.
+ * @returns {void}
+ */
+function forwardCurrentToHead(analyzer, node) {
+    const codePath = analyzer.codePath
+    const state = CodePath.getState(codePath)
+    const currentSegments = state.currentSegments
+    const headSegments = state.headSegments
+    const end = Math.max(currentSegments.length, headSegments.length)
+    let i = 0
+    let currentSegment = null
+    let headSegment = null
+
+    // Fires leaving events.
+    for (i = 0; i < end; ++i) {
+        currentSegment = currentSegments[i]
+        headSegment = headSegments[i]
+
+        if (currentSegment !== headSegment && currentSegment) {
+            if (currentSegment.reachable) {
+                analyzer.emitter.emit(
+                    "onCodePathSegmentEnd",
+                    currentSegment,
+                    node
+                )
+            }
+        }
+    }
+
+    // Update state.
+    state.currentSegments = headSegments
+
+    // Fires entering events.
+    for (i = 0; i < end; ++i) {
+        currentSegment = currentSegments[i]
+        headSegment = headSegments[i]
+
+        if (currentSegment !== headSegment && headSegment) {
+            CodePathSegment.markUsed(headSegment)
+            if (headSegment.reachable) {
+                analyzer.emitter.emit(
+                    "onCodePathSegmentStart",
+                    headSegment,
+                    node
+                )
+            }
+        }
+    }
+}
+
+/**
+ * Checks whether a given node is `assert.fail()` or not.
+ *
+ * @param {ASTNode} node - A node to check.
+ * @returns {boolean} `true` if the node is `assert.fail()`.
+ */
+function isAssertFail(node) {
+    return (
+        node.type === "CallExpression" &&
+        node.callee.type === "MemberExpression" &&
+        node.callee.computed === false &&
+        node.callee.object.type === "Identifier" &&
+        node.callee.object.name === "assert" &&
+        node.callee.property.type === "Identifier" &&
+        node.callee.property.name === "fail"
+    )
+}
+
+/**
+ * The function to override `CodePathAnalyzer.prototype.leaveNode` in order to
+ * address `assert.fail()` as throw.
+ *
+ * @this CodePathAnalyzer
+ * @param {ASTNode} node - A node to be left.
+ * @returns {void}
+ */
+function overrideLeaveNode(node) {
+    if (isAssertFail(node)) {
+        this.currentNode = node
+
+        forwardCurrentToHead(this, node)
+        CodePath.getState(this.codePath).makeThrow()
+
+        this.original.leaveNode(node)
+        this.currentNode = null
+    } else {
+        originalLeaveNode.call(this, node)
+    }
+}
+
+const visitor =
+    CodePathAnalyzer == null
+        ? {}
+        : {
+              Program: function installAssertFailAsThrow() {
+                  CodePathAnalyzer.prototype.leaveNode = overrideLeaveNode
+              },
+              "Program:exit": function restoreAssertFailAsThrow() {
+                  CodePathAnalyzer.prototype.leaveNode = originalLeaveNode
+              },
+          }
+
+module.exports = {
+    meta: {
+        docs: {
+            description:
+                "make `assert.fail()` expressions the same code path as `throw`",
+            category: "Possible Errors",
+            recommended: true,
+            url:
+                "https://github.com/Agoric/agoric-sdk/blob/master/packages/eslint-plugin/lib/rules/assert-fail-as-throw.js",
+        },
+        type: "problem",
+        fixable: null,
+        schema: [],
+        supported: true || CodePathAnalyzer != null,
+    },
+    create() {
+        return visitor
+    },
+}

packages/eslint-plugin/package.json

@@ -0,0 +1,33 @@
+{
+  "name": "@agoric/eslint-plugin",
+  "version": "0.0.0",
+  "description": "Agoric-specific ESLint plugin",
+  "keywords": [
+    "eslint",
+    "eslintplugin",
+    "eslint-plugin"
+  ],
+  "author": "Agoric",
+  "main": "lib/index.js",
+  "scripts": {
+    "test": "exit 0",
+    "build": "exit 0",
+    "lint-fix": "exit 0",
+    "lint-check": "exit 0"
+  },
+  "dependencies": {
+    "requireindex": "~1.1.0"
+  },
+  "devDependencies": {
+    "eslint": "^6.8.0",
+    "mocha": "^3.1.2"
+  },
+  "engines": {
+    "node": ">=0.10.0"
+  },
+  "prettier": {
+    "trailingComma": "all",
+    "singleQuote": true
+  },
+  "license": "Apache-2.0"
+}