Add a rule which shows an error when template can't be parsed by pug

Author: ezhlobo

index.js

@@ -5,6 +5,7 @@
 
 /* eslint-disable global-require */
 const allRules = {
+  'no-broken-template': require('./lib/rules/no-broken-template'),
   'no-undef': require('./lib/rules/no-undef'),
   'uses-react': require('./lib/rules/uses-react'),
   'uses-vars': require('./lib/rules/uses-vars'),
@@ -19,6 +20,7 @@ module.exports = {
         pug: true,
       },
       rules: {
+        'react-pug/no-broken-template': 2,
         'react-pug/no-undef': 2,
         'react-pug/uses-react': 2,
         'react-pug/uses-vars': 2,

lib/rules/no-broken-template.js

@@ -0,0 +1,48 @@
+/**
+ * @fileoverview Disallow broken template
+ * @author Eugene Zhlobo
+ */
+
+const { findVariablesInTemplate } = require('pug-uses-variables')
+const { isReactPugReference, getTemplate, buildLocation } = require('../utilities')
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: 'Disallow broken template',
+      category: 'Possible Errors',
+      recommended: true,
+    },
+    schema: [],
+  },
+
+  create: function (context) {
+    return {
+      TaggedTemplateExpression: function (node) {
+        if (isReactPugReference(node)) {
+          const template = getTemplate(node)
+
+          try {
+            findVariablesInTemplate(template)
+          } catch (error) {
+            const line = (error.line + node.loc.start.line) - 1
+            const source = error.src.split('\n')[error.line - 1]
+
+            context.report({
+              node,
+              loc: buildLocation(
+                [line, source.replace(/^([\s\t]+).*$/, '$1').length],
+                [line, source.length],
+              ),
+              message: 'Pug can\'t parse this template',
+            })
+          }
+        }
+      },
+    }
+  },
+}

lib/rules/no-undef.js

@@ -3,7 +3,12 @@
  * @author Eugene Zhlobo
  */
 
-const { isReactPugReference, getTemplate, extractVariables } = require('../utilities')
+const {
+  isReactPugReference,
+  getTemplate,
+  extractVariables,
+  buildLocation,
+} = require('../utilities')
 
 //------------------------------------------------------------------------------
 // Rule Definition
@@ -47,16 +52,10 @@ module.exports = {
           notDefinedVariables.forEach((variable) => {
             context.report({
               node,
-              loc: {
-                start: {
-                  line: (node.loc.start.line + variable.loc.start.line) - 1,
-                  column: variable.loc.start.column,
-                },
-                end: {
-                  line: (node.loc.start.line + variable.loc.end.line) - 1,
-                  column: variable.loc.end.column,
-                },
-              },
+              loc: buildLocation(
+                [(node.loc.start.line + variable.loc.start.line) - 1, variable.loc.start.column],
+                [(node.loc.start.line + variable.loc.end.line) - 1, variable.loc.end.column],
+              ),
               message: `'${variable.value}' is not defined.`,
             })
           })

lib/utilities.js

@@ -39,8 +39,22 @@ function extractVariables(template) {
   }
 }
 
+function buildLocation(startCoord, endCoord) {
+  return {
+    start: {
+      line: startCoord[0],
+      column: startCoord[1],
+    },
+    end: {
+      line: endCoord[0],
+      column: endCoord[1],
+    },
+  }
+}
+
 module.exports = {
   isReactPugReference,
   getTemplate,
   extractVariables,
+  buildLocation,
 }

tests/lib/rules/no-broken-template.js

@@ -0,0 +1,50 @@
+/**
+ * @fileoverview Tests for no-broken-template
+ * @author Eugene Zhlobo
+ */
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const eslint = require('eslint')
+
+const { RuleTester } = eslint
+
+const rule = require('../../../lib/rules/no-broken-template')
+
+const parserOptions = {
+  sourceType: 'module',
+}
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+const ruleTester = new RuleTester({ parserOptions })
+
+ruleTester.run('rule "no-broken-template"', rule, {
+  valid: [
+    { code: 'pug`p= variable`;' },
+    { code: 'pug`Component`;' },
+  ],
+  invalid: [
+    {
+      code: `
+        /*global pug*/
+        pug\`
+          p good string
+          div
+            each i in 1, 2, 3]
+        \`;
+      `,
+      errors: [{
+        line: 6,
+        column: 13,
+        endLine: 6,
+        endColumn: 31,
+        message: 'Pug can\'t parse this template',
+      }],
+    },
+  ],
+})