tools: add eslint rule for hasCrypto checking

The motivation for this commit is to pick up early on missing checks for
crypto support (when Node is built --without-ssl).

There are currently usages of common.hasCrypto which are not just for
detecting if crypto support is available and then skip the test in
question. For these case we still want to have a lint error generated
which can then be disabled using an ESLint comment.

PR-URL: https://github.com/nodejs/node/pull/13813
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Teddy Katz <teddy.katz@gmail.com>

test/.eslintrc.yaml

@@ -10,5 +10,6 @@ rules:
   prefer-assert-iferror: error
   prefer-assert-methods: error
   prefer-common-mustnotcall: error
+  crypto-check: error
   ## common module is mandatory in tests
   required-modules: [error, common]

test/common/index.js

@@ -19,7 +19,7 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-/* eslint-disable required-modules */
+/* eslint-disable required-modules, crypto-check */
 'use strict';
 const path = require('path');
 const fs = require('fs');

test/parallel/test-async-wrap-getasyncid.js

@@ -81,14 +81,14 @@ function testInitialized(req, ctor_name) {
 }
 
 
-if (common.hasCrypto) {
+if (common.hasCrypto) { // eslint-disable-line crypto-check
   const tls = require('tls');
   // SecurePair
   testInitialized(tls.createSecurePair().ssl, 'Connection');
 }
 
 
-if (common.hasCrypto) {
+if (common.hasCrypto) { // eslint-disable-line crypto-check
   const crypto = require('crypto');
 
   // The handle for PBKDF2 and RandomBytes isn't returned by the function call,
@@ -215,7 +215,7 @@ if (common.hasCrypto) {
 }
 
 
-if (common.hasCrypto) {
+if (common.hasCrypto) { // eslint-disable-line crypto-check
   const TCP = process.binding('tcp_wrap').TCP;
   const tcp = new TCP();
 

test/parallel/test-buffer-alloc.js

@@ -909,7 +909,7 @@ assert.throws(() => Buffer.from('', 'buffer'),
   }
 }
 
-if (common.hasCrypto) {
+if (common.hasCrypto) { // eslint-disable-line crypto-check
   // Test truncation after decode
   const crypto = require('crypto');
 

test/parallel/test-buffer-concat.js

@@ -62,6 +62,7 @@ function assertWrongList(value) {
   }));
 }
 
+// eslint-disable-next-line crypto-check
 const random10 = common.hasCrypto ?
   require('crypto').randomBytes(10) :
   Buffer.alloc(10, 1);

test/parallel/test-http2-noflag.js

@@ -4,5 +4,5 @@
 require('../common');
 const assert = require('assert');
 
-assert.throws(() => require('http2'),
+assert.throws(() => require('http2'), // eslint-disable-line crypto-check
               /^Error: Cannot find module 'http2'$/);

tools/eslint-rules/crypto-check.js

@@ -0,0 +1,83 @@
+/**
+ * @fileoverview Check that common.hasCrypto is used if crypto, tls,
+ * https, or http2 modules are required.
+ *
+ * This rule can be ignored using // eslint-disable-line crypto-check
+ *
+ * @author Daniel Bevenius <daniel.bevenius@gmail.com>
+ */
+'use strict';
+
+const utils = require('./rules-utils.js');
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+const msg = 'Please add a hasCrypto check to allow this test to be skipped ' +
+            'when Node is built "--without-ssl".';
+
+module.exports = function(context) {
+  const missingCheckNodes = [];
+  const requireNodes = [];
+  var hasSkipCall = false;
+
+  function testCryptoUsage(node) {
+    if (utils.isRequired(node, ['crypto', 'tls', 'https', 'http2'])) {
+      requireNodes.push(node);
+    }
+  }
+
+  function testIfStatement(node) {
+    if (node.test.argument === undefined) {
+      return;
+    }
+    if (isCryptoCheck(node.test.argument)) {
+      checkCryptoCall(node);
+    }
+  }
+
+  function isCryptoCheck(node) {
+    return utils.usesCommonProperty(node, ['hasCrypto', 'hasFipsCrypto']);
+  }
+
+  function checkCryptoCall(node) {
+    if (utils.inSkipBlock(node)) {
+      hasSkipCall = true;
+    } else {
+      missingCheckNodes.push(node);
+    }
+  }
+
+  function testMemberExpression(node) {
+    if (isCryptoCheck(node)) {
+      checkCryptoCall(node);
+    }
+  }
+
+  function reportIfMissingCheck(node) {
+    if (hasSkipCall) {
+      return;
+    }
+
+    if (requireNodes.length > 0) {
+      if (missingCheckNodes.length > 0) {
+        report(missingCheckNodes);
+      } else {
+        report(requireNodes);
+      }
+    }
+  }
+
+  function report(nodes) {
+    nodes.forEach((node) => {
+      context.report(node, msg);
+    });
+  }
+
+  return {
+    'CallExpression': (node) => testCryptoUsage(node),
+    'IfStatement:exit': (node) => testIfStatement(node),
+    'MemberExpression:exit': (node) => testMemberExpression(node),
+    'Program:exit': (node) => reportIfMissingCheck(node)
+  };
+};

tools/eslint-rules/rules-utils.js

@@ -0,0 +1,61 @@
+/**
+ * Utility functions common to ESLint rules.
+ */
+'use strict';
+
+/**
+ * Returns true if any of the passed in modules are used in
+ * require calls.
+ */
+module.exports.isRequired = function(node, modules) {
+  return node.callee.name === 'require' &&
+    modules.includes(node.arguments[0].value);
+};
+
+/**
+ * Returns true is the node accesses any property in the properties
+ * array on the 'common' object.
+ */
+module.exports.usesCommonProperty = function(node, properties) {
+  if (node.name) {
+    return properties.includes(node.name);
+  }
+  if (node.property) {
+    return properties.includes(node.property.name);
+  }
+  return false;
+};
+
+/**
+ * Returns true if the passed in node is inside an if statement block,
+ * and the block also has a call to skip.
+ */
+module.exports.inSkipBlock = function(node) {
+  var hasSkipBlock = false;
+  if (node.test &&
+      node.test.type === 'UnaryExpression' &&
+      node.test.operator === '!') {
+    const consequent = node.consequent;
+    if (consequent.body) {
+      consequent.body.some(function(expressionStatement) {
+        if (hasSkip(expressionStatement.expression)) {
+          return hasSkipBlock = true;
+        }
+        return false;
+      });
+    } else {
+      if (hasSkip(consequent.expression)) {
+        hasSkipBlock = true;
+      }
+    }
+  }
+  return hasSkipBlock;
+};
+
+function hasSkip(expression) {
+  return expression &&
+         expression.callee &&
+         (expression.callee.name === 'skip' ||
+         expression.callee.property &&
+         expression.callee.property.name === 'skip');
+}