Refactored and released as 0.0.4 with tests!

Author: Steve Purcell

Gemfile

@@ -2,3 +2,6 @@ source "https://rubygems.org"
 
 gem "pg_query"
 
+group :development do
+  gem "rspec"
+end

Gemfile.lock

@@ -1,15 +1,30 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    diff-lcs (1.2.5)
     json (1.8.3)
     pg_query (0.5.0)
       json (~> 1.8)
+    rspec (3.2.0)
+      rspec-core (~> 3.2.0)
+      rspec-expectations (~> 3.2.0)
+      rspec-mocks (~> 3.2.0)
+    rspec-core (3.2.3)
+      rspec-support (~> 3.2.0)
+    rspec-expectations (3.2.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.2.0)
+    rspec-mocks (3.2.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.2.0)
+    rspec-support (3.2.2)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   pg_query
+  rspec
 
 BUNDLED WITH
    1.10.3

Rakefile

@@ -0,0 +1,7 @@
+begin
+  require 'rspec/core/rake_task'
+  RSpec::Core::RakeTask.new(:spec)
+rescue LoadError
+end
+
+task default: :spec

bin/sqlint

@@ -1,5 +1,10 @@
 #!/usr/bin/env ruby
 
+# What if 1000+ errors => --limit
+# Split on "; -- ..."
+
+
+
 $LOAD_PATH.unshift(File.dirname(File.realpath(__FILE__)) + '/../lib')
 require 'pg_query'
 require 'sqlint'
@@ -9,20 +14,22 @@ if ARGV.include?("--version")
   exit 0
 end
 
+ERROR_TYPES = {error: "ERROR", warning: "WARNING"}
+
 ARGV.each do |filename|
-  contents = File.read(filename)
-  begin
-    PgQuery.parse(File.read(filename))
-  rescue PgQuery::ParseError => e
-    offset = e.location
-    before_error = contents[0...(offset-1)]
-    lines = before_error.split("\n")
-    line_number = lines.size
-    column_number = lines.last.size
-    message_lines = e.message.split("\n")
-    puts [filename, line_number, column_number, "ERROR " + message_lines.shift].join(":")
-    message_lines.each do |line|
-      puts "  " + line
+  File.open(filename, 'r') do |file|
+    results = SQLint::Linter.new(filename, file).run
+    results.each do |lint|
+      message_lines = lint.message.split("\n")
+      puts [
+        lint.filename,
+        lint.line,
+        lint.column,
+        ERROR_TYPES[lint.type] + " " + message_lines.shift
+      ].join(":")
+      message_lines.each do |line|
+        puts "  " + line
+      end
     end
   end
 end

lib/sqlint.rb

@@ -1 +1,2 @@
 require 'sqlint/version'
+require 'sqlint/linter'

lib/sqlint/linter.rb

@@ -0,0 +1,26 @@
+require 'pg_query'
+
+module SQLint
+  class Linter
+    Lint = Struct.new(:filename, :line, :column, :type, :message)
+
+    def initialize(filename, input_stream)
+      @input = input_stream.read
+      @filename = filename
+    end
+
+    def run
+      [].tap do |results|
+        begin
+          PgQuery.parse(@input)
+        rescue PgQuery::ParseError => e
+          offset = e.location
+          lines_before_error = @input[0...(offset)].split("\n")
+          line_number = lines_before_error.size
+          column_number = lines_before_error.any? ? lines_before_error.last.size : 1
+          results << Lint.new(@filename, line_number, column_number, :error, e.message)
+        end
+      end
+    end
+  end
+end

lib/sqlint/version.rb

@@ -1,3 +1,3 @@
 module SQLint
-  VERSION = "0.0.3"
+  VERSION = "0.0.4"
 end

spec/sqlint_spec.rb

@@ -0,0 +1,58 @@
+require_relative '../lib/sqlint'
+
+RSpec.describe SQLint do
+
+  let(:filename) { "some/file/here.sql" }
+  let(:input) { "SELECT 1" }
+  let(:input_stream) { StringIO.new(input) }
+  subject(:linter) { SQLint::Linter.new(filename, input_stream) }
+  let(:results) { linter.run }
+
+  def error(line, col, msg)
+    SQLint::Linter::Lint.new(filename, line, col, :error, msg)
+  end
+
+  def warning(line, col, msg)
+    SQLint::Linter::Lint.new(filename, line, col, :warning, msg)
+  end
+
+  context "with empty input" do
+    let(:input) { "" }
+
+    it "reports no errors" do
+      expect(results).to be_empty
+    end
+  end
+
+  describe "single errors" do
+    context "with a single valid statement" do
+      it "reports no errors" do
+        expect(results).to be_empty
+      end
+    end
+
+    context "with a single invalid keyword" do
+      let(:input) { "WIBBLE" }
+      it "reports one error" do
+        expect(results.size).to eq(1)
+        expect(results.first).to eq(error(1, 1, 'syntax error at or near "WIBBLE"'))
+      end
+    end
+
+    context "with a single invalid keyword on a later line" do
+      let(:input) { "SELECT 1;\nWIBBLE" }
+      it "reports one error" do
+        expect(results.size).to eq(1)
+        expect(results.first).to eq(error(2, 1, 'syntax error at or near "WIBBLE"'))
+      end
+    end
+
+    context "with a single error part-way through a line" do
+      let(:input) { "SELECT '" }
+      it "reports one error" do
+        expect(results.size).to eq(1)
+        expect(results.first).to eq(error(1, 8, 'unterminated quoted string at or near "\'"'))
+      end
+    end
+  end
+end