feat: SQL comments support

Add SQL comments support, including MySQL # comments.

Refs: #133

README.md

@@ -89,6 +89,7 @@ The following options may be passed to the `highlight` function.
   string: '\x1b[32m',   // Strings
   special: '\x1b[33m',  // Special characters
   bracket: '\x1b[33m',  // Brackets (parentheses)
+  comment: '\x1b[2m\x1b[90m', // Comments
   clear: '\x1b[0m'      // Clear (inserted after each match)
 }
 ```

lib/index.d.ts

@@ -10,6 +10,7 @@ declare module 'sql-highlight' {
       string: string;
       special: string;
       bracket: string;
+      comment: string;
       clear: string;
     };
   }

lib/index.js

@@ -14,6 +14,7 @@ const DEFAULT_OPTIONS = {
     string: '\x1b[32m',
     special: '\x1b[33m',
     bracket: '\x1b[33m',
+    comment: '\x1b[2m\x1b[90m',
     clear: '\x1b[0m'
   }
 }
@@ -26,6 +27,9 @@ const highlighters = [
   // Note: Repeating string escapes like 'sql''server' will also work as they are just repeating strings
   /(?<string>'(?:[^'\\]|\\.)*'|"(?:[^"\\]|\\.)*"|`(?:[^`\\]|\\.)*`)/,
 
+  /(?<comment>--[^\n\r]*|#[^\n\r]*|\/\*(?:[^*]|\*(?!\/))*\*\/)/,
+
+  // Future improvement: Comments should be allowed between the function name and the opening parenthesis
   /\b(?<function>\w+)(?=\s*\()/,
 
   /(?<bracket>[()])/,

test/debug.js

@@ -26,4 +26,6 @@ console.log(highlight('DROP PROCEDURE IF EXISTS `some-database`.`some-table`;'))
 
 console.log(highlight('SELECT * FROM a;SELECT * FROM b;'))
 
+console.log(highlight('SELECT foo /* comment, not "keyword" WHERE GROUP */ FROM bar; -- comment\nSELECT * FROM baz;'))
+
 console.log(highlight("select * from a where b = 'array<map<string,string>>';", { html: true }))

test/index.test.js

@@ -8,6 +8,7 @@ const OPTIONS = {
     string: '[string]',
     special: '[special]',
     bracket: '[bracket]',
+    comment: '[comment]',
     clear: '[clear]'
   }
 }
@@ -114,6 +115,26 @@ describe('unicode', () => {
     expect(hlUni('SELECT * FROM a;SELECT * FROM b;'))
       .toBe('[keyword]SELECT[clear] [special]*[clear] [keyword]FROM[clear] a[special];[clear][keyword]SELECT[clear] [special]*[clear] [keyword]FROM[clear] b[special];[clear]')
   })
+
+  it('comment single line', () => {
+    expect(hlUni('-- comment 1 "comment" /* still */ comment 2\nSELECT `not comment`; -- comment 3'))
+      .toBe('[comment]-- comment 1 "comment" /* still */ comment 2[clear]\n[keyword]SELECT[clear] [string]`not comment`[clear][special];[clear] [comment]-- comment 3[clear]')
+  })
+
+  it('comment mysql', () => {
+    expect(hlUni('# comment 1 "comment" /* still */ comment 2\nSELECT `not comment`; # comment 3'))
+      .toBe('[comment]# comment 1 "comment" /* still */ comment 2[clear]\n[keyword]SELECT[clear] [string]`not comment`[clear][special];[clear] [comment]# comment 3[clear]')
+  })
+
+  it('comment multiline', () => {
+    expect(hlUni('SELECT /* this is, a "comment" */ "not /*comment*/" /***also*comment***/'))
+      .toBe('[keyword]SELECT[clear] [comment]/* this is, a "comment" */[clear] [string]"not /*comment*/"[clear] [comment]/***also*comment***/[clear]')
+  })
+
+  it('not a comment', () => {
+    expect(hlUni('"id -- not comment /* still */ not"'))
+      .toBe('[string]"id -- not comment /* still */ not"[clear]')
+  })
 })
 
 describe('html', () => {
@@ -211,6 +232,26 @@ describe('html', () => {
     expect(hlHtml("select * from a where b = 'array<map<string,string>>';"))
       .toBe('<span class="sql-hl-keyword">select</span> <span class="sql-hl-special">*</span> <span class="sql-hl-keyword">from</span> a <span class="sql-hl-keyword">where</span> b <span class="sql-hl-special">=</span> <span class="sql-hl-string">&#39;array&lt;map&lt;string,string&gt;&gt;&#39;</span><span class="sql-hl-special">;</span>')
   })
+
+  it('comment single line', () => {
+    expect(hlHtml('-- comment 1 "comment" /* still */ comment 2\nSELECT `not comment`; -- comment 3'))
+      .toBe('<span class="sql-hl-comment">-- comment 1 &quot;comment&quot; /* still */ comment 2</span>\n<span class="sql-hl-keyword">SELECT</span> <span class="sql-hl-string">`not comment`</span><span class="sql-hl-special">;</span> <span class="sql-hl-comment">-- comment 3</span>')
+  })
+
+  it('comment mysql', () => {
+    expect(hlHtml('# comment 1 "comment" /* still */ comment 2\nSELECT `not comment`; # comment 3'))
+      .toBe('<span class="sql-hl-comment"># comment 1 &quot;comment&quot; /* still */ comment 2</span>\n<span class="sql-hl-keyword">SELECT</span> <span class="sql-hl-string">`not comment`</span><span class="sql-hl-special">;</span> <span class="sql-hl-comment"># comment 3</span>')
+  })
+
+  it('comment multiline', () => {
+    expect(hlHtml('SELECT /* this is, a "comment" */ "not /*comment*/" /***also*comment***/'))
+      .toBe('<span class="sql-hl-keyword">SELECT</span> <span class="sql-hl-comment">/* this is, a &quot;comment&quot; */</span> <span class="sql-hl-string">&quot;not /*comment*/&quot;</span> <span class="sql-hl-comment">/***also*comment***/</span>')
+  })
+
+  it('not a comment', () => {
+    expect(hlHtml('"id -- not comment /* still */ not"'))
+      .toBe('<span class="sql-hl-string">&quot;id -- not comment /* still */ not&quot;</span>')
+  })
 })
 
 describe('getSegments', () => {