feat: port HCL2 parser from spandx

* https://github.com/spandx/spandx/blob/dc7ea719adbf2e90753cb92be76e21cddc916557/lib/spandx/terraform/parsers/hcl.rb

10 files changed, 590 insertions, 0 deletions

diff --git a/Gemfile.lock b/Gemfile.lock
index 4d1aefd..5568bba 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,6 +2,7 @@ PATH
   remote: .
   specs:
     hcl2 (0.1.0)
+      parslet (~> 2.0)
 
 GEM
   remote: https://rubygems.org/
@@ -11,6 +12,7 @@ GEM
     parallel (1.20.1)
     parser (3.0.1.1)
       ast (~> 2.4.1)
+    parslet (2.0.0)
     rainbow (3.0.0)
     rake (13.0.3)
     regexp_parser (2.1.1)
diff --git a/hcl2.gemspec b/hcl2.gemspec
index e8c5c70..191670c 100644
--- a/hcl2.gemspec
+++ b/hcl2.gemspec
@@ -26,4 +26,5 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{\Aexe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
+  spec.add_dependency 'parslet', '~> 2.0'
 end
diff --git a/lib/hcl2.rb b/lib/hcl2.rb
index fa7b2e7..e6f2fb8 100644
--- a/lib/hcl2.rb
+++ b/lib/hcl2.rb
@@ -1,7 +1,109 @@
 # frozen_string_literal: true
 
+require "parslet"
 require_relative "hcl2/version"
 
 module Hcl2
   class Error < StandardError; end
+
+  class Parser < ::Parslet::Parser
+    rule(:alpha) { match['a-zA-Z'] }
+    rule(:assign) { str('=') }
+    rule(:colon) { str(':') }
+    rule(:comma) { str(',') }
+    rule(:comment) { (str('#') | str('//')) >> ((str("\n") >> str("\r").maybe).absent? >> any).repeat >> eol }
+    rule(:crlf) { match('[\r\n]') }
+    rule(:digit) { match('\d') }
+    rule(:dot) { str('.') }
+    rule(:eol) { whitespace? >> crlf.repeat }
+    rule(:greater_than_or_equal_to) { str('>=') }
+    rule(:hyphen) { str('-') }
+    rule(:lbracket) { str('[') }
+    rule(:lcurly) { str('{') }
+    rule(:major) { number }
+    rule(:major_minor) { (number >> dot >> number) }
+    rule(:major_minor_patch) { number >> dot >> number >> dot >> number }
+    rule(:multiline_comment) { str('/*') >> (str('*/').absent? >> any).repeat >> str('*/') }
+    rule(:number) { digit.repeat }
+    rule(:plus) { str('+') }
+    rule(:pre_release) { hyphen >> (alpha | digit).repeat }
+    rule(:pre_release?) { pre_release.maybe }
+    rule(:quote) { str('"') }
+    rule(:rbracket) { str(']') }
+    rule(:rcurly) { str('}') }
+    rule(:slash) { str('/') }
+    rule(:space) { match('\s') }
+    rule(:tilda_wacka) { str('~>') }
+    rule(:version) { number >> dot >> number >> dot >> number >> pre_release? }
+    rule(:whitespace) { (multiline_comment | comment | space).repeat }
+    rule(:whitespace?) { whitespace.maybe }
+
+    rule(:pessimistic_version_constraint) do
+      tilda_wacka >> whitespace >> (
+        major_minor_patch |
+        major_minor |
+        major
+      )
+    end
+
+    rule(:greater_than_or_equal_to_version) do
+      greater_than_or_equal_to >> whitespace >> (
+        major_minor_patch |
+        major_minor |
+        major
+      )
+    end
+
+    rule(:version_constraint) do
+      pessimistic_version_constraint | greater_than_or_equal_to_version
+    end
+
+    rule :version_assignment do
+      str('version') >> whitespace >> assign >> whitespace >> quote >> version.as(:version) >> quote
+    end
+
+    rule :constraint_assignment do
+      str('constraints') >> whitespace >> assign >> whitespace >> quote >> version_constraint.as(:constraints) >> quote
+    end
+
+    rule :string do
+      quote >> (
+        digit | dot | alpha | str('~> ') | slash | colon | assign | plus
+      ).repeat(1).as(:value) >> quote
+    end
+
+    rule :array_item do
+      whitespace? >> string >> comma.maybe >> eol
+    end
+
+    rule :array do
+      lbracket >> eol >> array_item.repeat >> whitespace >> rbracket
+    end
+
+    rule :argument_value do
+      (array.as(:values) | string) >> eol
+    end
+
+    rule :argument do
+      whitespace >> alpha.repeat(1).as(:name) >> whitespace >> assign >> whitespace >> argument_value
+    end
+
+    rule :block_body do
+      lcurly >> crlf >> argument.repeat.as(:arguments) >> rcurly
+    end
+
+    rule :identifier do
+      whitespace >> quote >> (alpha | dot | slash).repeat(1).as(:name) >> quote >> whitespace
+    end
+
+    rule :block do
+      alpha.repeat(1).as(:type) >> identifier >> block_body
+    end
+
+    rule :blocks do
+      whitespace? >> (block >> eol.maybe).repeat(1).as(:blocks)
+    end
+
+    root(:blocks)
+  end
 end
diff --git a/spec/fixtures/terraform/multiple_providers/.terraform.lock.hcl b/spec/fixtures/terraform/multiple_providers/.terraform.lock.hcl
new file mode 100644
index 0000000..b0ca24f
--- /dev/null
+++ b/spec/fixtures/terraform/multiple_providers/.terraform.lock.hcl
@@ -0,0 +1,40 @@
+# This file is maintained automatically by "terraform init".
+# Manual edits may be lost in future updates.
+
+provider "registry.terraform.io/hashicorp/aws" {
+  version     = "3.40.0"
+  constraints = "~> 3.27"
+  hashes = [
+    "h1:0r9TS3qACD9xJhrfTPZR7ygoCKDWHRX4c0D5GCyfAu4=",
+    "zh:2fd824991b19837e200d19b17d8188bf71efb92c36511809484549e77b4045dd",
+    "zh:47250cb58b3bd6f2698ca17bfb962710542d6adf95637cd560f6119abf97dba2",
+    "zh:515722a8c8726541b05362ec71331264977603374a2e4d4d64f89940873143ea",
+    "zh:61b6b7542da2113278c987a0af9f230321f5ed605f1e3098824603cb09ac771b",
+    "zh:66aad13ada6344b64adbc67abad4f35c414e62838a99f78626befb8b74c760d8",
+    "zh:7d4436aeb53fa348d7fd3c2ab4a727b03c7c59bfdcdecef4a75237760f3bb3cf",
+    "zh:a4583891debc49678491510574b1c28bb4fe3f83ed2bb353959c4c1f6f409f1f",
+    "zh:b8badecea52f6996ae832144560be87e0b7c2da7fe1dcd6e6230969234b2fc55",
+    "zh:cecf64a085f640c30437ccc31bd964c21004ae8ae00cfbd95fb04037e46b88ca",
+    "zh:d81dbb9ad8ce5eca4d1fc5a7a06bbb9c47ea8691f1502e94760fa680e20e4afc",
+    "zh:f0fc724a964c7f8154bc5911d572ee411f5d181414f9b1f09de7ebdacb0d884b",
+  ]
+}
+
+provider "registry.terraform.io/hashicorp/azurerm" {
+  version     = "2.59.0"
+  constraints = "~> 2.1"
+  hashes = [
+    "h1:Mp7ECMHocobalN1+ASSKG5dHB7RnhZ6Y0rEEFTT5urA=",
+    "zh:0996d1c85bccdb15aeb6bc32f763c2d85ff854b33c3c3d62c34859669e05785e",
+    "zh:37807677e68058381514897ce10dc73a0dd0f503aba98113ac79844d310010e3",
+    "zh:3bccf9215bdbcc89327582b1d9d2a633c59215ca6452dbb4f9d0a7a661074c5b",
+    "zh:4801791332ab81e51d1ead47a62e0081ec4c1f23ef0fc2e8b15fef315ecdf07a",
+    "zh:5bad44816a3eaeb335f665f6eef9b41a403a40e9bddb2db8406ab0e847f639ca",
+    "zh:64f79c4ddc2bf8384f1a42c4e430ffdc53cb1fbc565bfe1cdc6b075dcdf098e9",
+    "zh:75c96fcb592ed80cc403944faadda25aeadda7fd6de9162a8d365249b1ec1c17",
+    "zh:8604558f2f201eefe25f4c611a5d4ef4d7c75338bf2f4a6321da5caa94937947",
+    "zh:cab930e374d33b3b980c6774f3d0ac3e3d7e1e596aba586d4368d8bcf05cf9c5",
+    "zh:cf0e78eb1e84b6dd11031283878e392e55801e3acd9c5592309e6f76ebe3a621",
+    "zh:eba02fcab150775b8b8beeec0c7dbba1585a57f4e97272f48c71021c5e289579",
+  ]
+}
diff --git a/spec/fixtures/terraform/multiple_providers/main.tf b/spec/fixtures/terraform/multiple_providers/main.tf
new file mode 100644
index 0000000..e2e0818
--- /dev/null
+++ b/spec/fixtures/terraform/multiple_providers/main.tf
@@ -0,0 +1,12 @@
+terraform {
+  required_providers {
+    aws = {
+      source = "hashicorp/aws"
+      version = "~> 3.27"
+    }
+    azure = {
+      source = "hashicorp/azurerm"
+      version = "~> 2.1"
+    }
+  }
+}
diff --git a/spec/fixtures/terraform/simple/.terraform.lock.hcl b/spec/fixtures/terraform/simple/.terraform.lock.hcl
new file mode 100644
index 0000000..9a41a4c
--- /dev/null
+++ b/spec/fixtures/terraform/simple/.terraform.lock.hcl
@@ -0,0 +1,21 @@
+# This file is maintained automatically by "terraform init".
+# Manual edits may be lost in future updates.
+
+provider "registry.terraform.io/hashicorp/aws" {
+  version     = "3.39.0"
+  constraints = "~> 3.27"
+  hashes = [
+    "h1:fjlp3Pd3QsTLghNm7TUh/KnEMM2D3tLb7jsDLs8oWUE=",
+    "zh:2014b397dd93fa55f2f2d1338c19e5b2b77b025a76a6b1fceea0b8696e984b9c",
+    "zh:23d59c68ab50148a0f5c911a801734e9934a1fccd41118a8efb5194135cbd360",
+    "zh:412eab41d4934ca9c47083faa128e4cd585c3bb44ad718e40d67091aebc02f4e",
+    "zh:4b75e0a259b56d97e66b7d69f3f25bd4cc7be2440c0fe35529f46de7d40a49d3",
+    "zh:694a32519dcca5bd8605d06481d16883d55160d97c1f4039deb13c6ca8de8427",
+    "zh:6a0bcef43c2d9a97aeaaac3c5d1d6728dc2464a51a014f118c691c79029d0903",
+    "zh:6d78fc7c663247ca2a80f276008dcdafece4cac75e2639bbce188c08b796040a",
+    "zh:78f846a505d7b64b67feed1527d4d2b40130dadaf8e3112113685e148f49b156",
+    "zh:881bc969432d3ef6ec70f5a762c3415e037904338579b0a360c6818b74d26e59",
+    "zh:96c1ca80c1d693a3eef80489adb45c076ee8e6878e461d6c29b05388d4b95f48",
+    "zh:9be5fa342272586fc6e319e20f21c0c5c801b05dcf7d59e473ad0882c9ecfa70",
+  ]
+}
diff --git a/spec/fixtures/terraform/simple/main.tf b/spec/fixtures/terraform/simple/main.tf
new file mode 100644
index 0000000..b025be8
--- /dev/null
+++ b/spec/fixtures/terraform/simple/main.tf
@@ -0,0 +1,15 @@
+terraform {
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 3.27"
+    }
+  }
+
+  required_version = ">= 0.14.9"
+}
+
+provider "aws" {
+  profile = "default"
+  region  = "ca-central-1"
+}
diff --git a/spec/parser_spec.rb b/spec/parser_spec.rb
new file mode 100644
index 0000000..0e356ea
--- /dev/null
+++ b/spec/parser_spec.rb
@@ -0,0 +1,380 @@
+# frozen_string_literal: true
+
+RSpec.describe Hcl2::Parser do
+  subject(:parser) { described_class.new }
+
+  describe '#parse' do
+    subject { parser.parse_with_debug(content) }
+
+    context 'when parsing a single provider' do
+      let(:content) do
+        <<~HCL
+          # This file is maintained automatically by "terraform init".
+          # Manual edits may be lost in future updates.
+
+          provider "registry.terraform.io/hashicorp/aws" {
+            version     = "3.39.0"
+            constraints = "~> 3.27"
+            hashes = [
+              "h1:fjlp3Pd3QsTLghNm7TUh/KnEMM2D3tLb7jsDLs8oWUE=",
+              "zh:2014b397dd93fa55f2f2d1338c19e5b2b77b025a76a6b1fceea0b8696e984b9c",
+              "zh:23d59c68ab50148a0f5c911a801734e9934a1fccd41118a8efb5194135cbd360",
+              "zh:412eab41d4934ca9c47083faa128e4cd585c3bb44ad718e40d67091aebc02f4e",
+              "zh:4b75e0a259b56d97e66b7d69f3f25bd4cc7be2440c0fe35529f46de7d40a49d3",
+              "zh:694a32519dcca5bd8605d06481d16883d55160d97c1f4039deb13c6ca8de8427",
+              "zh:6a0bcef43c2d9a97aeaaac3c5d1d6728dc2464a51a014f118c691c79029d0903",
+              "zh:6d78fc7c663247ca2a80f276008dcdafece4cac75e2639bbce188c08b796040a",
+              "zh:78f846a505d7b64b67feed1527d4d2b40130dadaf8e3112113685e148f49b156",
+              "zh:881bc969432d3ef6ec70f5a762c3415e037904338579b0a360c6818b74d26e59",
+              "zh:96c1ca80c1d693a3eef80489adb45c076ee8e6878e461d6c29b05388d4b95f48",
+              "zh:9be5fa342272586fc6e319e20f21c0c5c801b05dcf7d59e473ad0882c9ecfa70",
+            ]
+          }
+
+          /*
+            This is a multi-line comment
+            that spans multiple lines
+          */
+        HCL
+      end
+
+      specify { expect(subject).to be_truthy }
+      specify { expect(subject[:blocks][0][:name].to_s).to eql('registry.terraform.io/hashicorp/aws') }
+      specify { expect(subject[:blocks][0][:type].to_s).to eql('provider') }
+
+      specify do
+        expect(subject[:blocks][0][:arguments]).to match_array([
+          { name: 'version', value: '3.39.0' },
+          { name: 'constraints', value: '~> 3.27' },
+          {
+            name: 'hashes',
+            values: [
+              { value: 'h1:fjlp3Pd3QsTLghNm7TUh/KnEMM2D3tLb7jsDLs8oWUE=' },
+              { value: 'zh:2014b397dd93fa55f2f2d1338c19e5b2b77b025a76a6b1fceea0b8696e984b9c' },
+              { value: 'zh:23d59c68ab50148a0f5c911a801734e9934a1fccd41118a8efb5194135cbd360' },
+              { value: 'zh:412eab41d4934ca9c47083faa128e4cd585c3bb44ad718e40d67091aebc02f4e' },
+              { value: 'zh:4b75e0a259b56d97e66b7d69f3f25bd4cc7be2440c0fe35529f46de7d40a49d3' },
+              { value: 'zh:694a32519dcca5bd8605d06481d16883d55160d97c1f4039deb13c6ca8de8427' },
+              { value: 'zh:6a0bcef43c2d9a97aeaaac3c5d1d6728dc2464a51a014f118c691c79029d0903' },
+              { value: 'zh:6d78fc7c663247ca2a80f276008dcdafece4cac75e2639bbce188c08b796040a' },
+              { value: 'zh:78f846a505d7b64b67feed1527d4d2b40130dadaf8e3112113685e148f49b156' },
+              { value: 'zh:881bc969432d3ef6ec70f5a762c3415e037904338579b0a360c6818b74d26e59' },
+              { value: 'zh:96c1ca80c1d693a3eef80489adb45c076ee8e6878e461d6c29b05388d4b95f48' },
+              { value: 'zh:9be5fa342272586fc6e319e20f21c0c5c801b05dcf7d59e473ad0882c9ecfa70' },
+            ]
+          },
+        ])
+      end
+    end
+
+    context 'when parsing multiple provider blocks' do
+      let(:content) { fixture_file_content('terraform/multiple_providers/.terraform.lock.hcl') }
+
+      specify { expect(subject).to be_truthy }
+      specify { expect(subject[:blocks][0][:name].to_s).to eql('registry.terraform.io/hashicorp/aws') }
+      specify { expect(subject[:blocks][0][:type].to_s).to eql('provider') }
+      specify { expect(subject[:blocks][1][:name].to_s).to eql('registry.terraform.io/hashicorp/azurerm') }
+      specify { expect(subject[:blocks][1][:type].to_s).to eql('provider') }
+
+      specify do
+        expect(subject[:blocks][0][:arguments]).to match_array([
+          { name: 'version', value: '3.40.0' },
+          { name: 'constraints', value: '~> 3.27' },
+          {
+            name: 'hashes',
+            values: [
+              { value: 'h1:0r9TS3qACD9xJhrfTPZR7ygoCKDWHRX4c0D5GCyfAu4=' },
+              { value: 'zh:2fd824991b19837e200d19b17d8188bf71efb92c36511809484549e77b4045dd' },
+              { value: 'zh:47250cb58b3bd6f2698ca17bfb962710542d6adf95637cd560f6119abf97dba2' },
+              { value: 'zh:515722a8c8726541b05362ec71331264977603374a2e4d4d64f89940873143ea' },
+              { value: 'zh:61b6b7542da2113278c987a0af9f230321f5ed605f1e3098824603cb09ac771b' },
+              { value: 'zh:66aad13ada6344b64adbc67abad4f35c414e62838a99f78626befb8b74c760d8' },
+              { value: 'zh:7d4436aeb53fa348d7fd3c2ab4a727b03c7c59bfdcdecef4a75237760f3bb3cf' },
+              { value: 'zh:a4583891debc49678491510574b1c28bb4fe3f83ed2bb353959c4c1f6f409f1f' },
+              { value: 'zh:b8badecea52f6996ae832144560be87e0b7c2da7fe1dcd6e6230969234b2fc55' },
+              { value: 'zh:cecf64a085f640c30437ccc31bd964c21004ae8ae00cfbd95fb04037e46b88ca' },
+              { value: 'zh:d81dbb9ad8ce5eca4d1fc5a7a06bbb9c47ea8691f1502e94760fa680e20e4afc' },
+              { value: 'zh:f0fc724a964c7f8154bc5911d572ee411f5d181414f9b1f09de7ebdacb0d884b' },
+            ]
+          },
+        ])
+      end
+
+      specify do
+        expect(subject[:blocks][1][:arguments]).to match_array([
+          { name: 'version', value: '2.59.0' },
+          { name: 'constraints', value: '~> 2.1' },
+          {
+            name: 'hashes',
+            values: [
+              { value: 'h1:Mp7ECMHocobalN1+ASSKG5dHB7RnhZ6Y0rEEFTT5urA=' },
+              { value: 'zh:0996d1c85bccdb15aeb6bc32f763c2d85ff854b33c3c3d62c34859669e05785e' },
+              { value: 'zh:37807677e68058381514897ce10dc73a0dd0f503aba98113ac79844d310010e3' },
+              { value: 'zh:3bccf9215bdbcc89327582b1d9d2a633c59215ca6452dbb4f9d0a7a661074c5b' },
+              { value: 'zh:4801791332ab81e51d1ead47a62e0081ec4c1f23ef0fc2e8b15fef315ecdf07a' },
+              { value: 'zh:5bad44816a3eaeb335f665f6eef9b41a403a40e9bddb2db8406ab0e847f639ca' },
+              { value: 'zh:64f79c4ddc2bf8384f1a42c4e430ffdc53cb1fbc565bfe1cdc6b075dcdf098e9' },
+              { value: 'zh:75c96fcb592ed80cc403944faadda25aeadda7fd6de9162a8d365249b1ec1c17' },
+              { value: 'zh:8604558f2f201eefe25f4c611a5d4ef4d7c75338bf2f4a6321da5caa94937947' },
+              { value: 'zh:cab930e374d33b3b980c6774f3d0ac3e3d7e1e596aba586d4368d8bcf05cf9c5' },
+              { value: 'zh:cf0e78eb1e84b6dd11031283878e392e55801e3acd9c5592309e6f76ebe3a621' },
+              { value: 'zh:eba02fcab150775b8b8beeec0c7dbba1585a57f4e97272f48c71021c5e289579' },
+            ]
+          },
+        ])
+      end
+    end
+  end
+
+  describe '#version_assignment' do
+    subject { parser.version_assignment }
+
+    [
+      'version     = "3.39.0"',
+      'version     = "3.39.0-alpha"',
+      'version     = "3.39.0-beta"',
+      'version     = "3.39.0-d15aad9f"',
+      'version     = "3.39.0-d15aad9f6ad69c4248a70b11a6534c1c841ec6f9"',
+      'version = "3.39.0"',
+      'version = "3.39.0-alpha"',
+      'version = "3.39.0-beta"',
+      'version = "3.39.0-d15aad9f"',
+      'version = "3.39.0-d15aad9f6ad69c4248a70b11a6534c1c841ec6f9"',
+    ].each do |raw|
+      specify { expect(subject).to parse(raw) }
+    end
+  end
+
+  describe '#version' do
+    [
+      '0.1.1-alpha',
+      '0.1.1-beta',
+      '1.2.3',
+      '3.39.0',
+      '3.39.0-d15aad9f',
+      '3.39.0-d15aad9f6ad69c4248a70b11a6534c1c841ec6f9',
+    ].each do |raw|
+      specify { expect(parser.version).to parse(raw) }
+    end
+  end
+
+  describe '#constraint_assignment' do
+    subject { parser.constraint_assignment }
+
+    [
+      'constraints = ">= 3"',
+      'constraints = ">= 3.27"',
+      'constraints = ">= 3.27.0"',
+      'constraints = "~> 3"',
+      'constraints = "~> 3.27"',
+      'constraints = "~> 3.27.0"',
+    ].each do |raw|
+      specify { expect(subject).to parse(raw) }
+    end
+  end
+
+  describe '#version_constraint' do
+    [
+      '~> 3',
+      '~> 3.27',
+      '~> 3.27.0',
+      '>= 1.2.0',
+      '>= 1.20',
+      '>= 10',
+    ].each do |raw|
+      specify { expect(parser.version_constraint).to parse(raw) }
+    end
+  end
+
+  (('a'..'z').to_a + ('A'..'Z').to_a).each do |letter|
+    specify { expect(parser.alpha).to parse(letter) }
+  end
+
+  (0..9).each { |digit| specify { expect(parser.digit).to parse(digit.to_s) } }
+  specify { expect(parser.assign).not_to parse('==') }
+  specify { expect(parser.assign).to parse('=') }
+  specify { expect(parser.comment).to parse('# Manual edits may be lost in future updates.') }
+  specify { expect(parser.comment).to parse('# This file is maintained automatically by "terraform init".') }
+  specify { expect(parser.comment).to parse('// This file is maintained automatically by "terraform init".') }
+  specify { expect(parser.crlf).to parse("\n") }
+  specify { expect(parser.crlf).to parse("\r") }
+  specify { expect(parser.dot).to parse('.') }
+  specify { expect(parser.eol).to parse(" \n") }
+  specify { expect(parser.eol).to parse("\n") }
+  specify { expect(parser.lcurly).to parse('{') }
+  specify { expect(parser.number).to parse('123') }
+  specify { expect(parser.quote).to parse('"') }
+  specify { expect(parser.rcurly).to parse('}') }
+  specify { expect(parser.space).to parse(' ') }
+  specify { expect(parser.whitespace).to parse('# This is a comment') }
+  specify { expect(parser.whitespace).to parse('// This is a comment') }
+  specify { expect(parser.string).to parse('"h1:fjlp3Pd3QsTLghNm7TUh/KnEMM2D3tLb7jsDLs8oWUE="') }
+  specify { expect(parser.string).to parse('"zh:2014b397dd93fa55f2f2d1338c19e5b2b77b025a76a6b1fceea0b8696e984b9c"') }
+
+  specify do
+    expect(parser.whitespace).to parse(<<~HCL)
+      /*
+        This is a multi-line comment
+        that spans multiple lines
+      */
+    HCL
+  end
+
+  specify { expect(parser.argument).to parse('constraints = "~> 3.27"') }
+
+  specify do
+    expect(parser.argument).to parse(<<~HCL.chomp)
+      hashes = [
+        "h1:fjlp3Pd3QsTLghNm7TUh/KnEMM2D3tLb7jsDLs8oWUE=",
+        "zh:2014b397dd93fa55f2f2d1338c19e5b2b77b025a76a6b1fceea0b8696e984b9c",
+        "zh:23d59c68ab50148a0f5c911a801734e9934a1fccd41118a8efb5194135cbd360",
+        "zh:412eab41d4934ca9c47083faa128e4cd585c3bb44ad718e40d67091aebc02f4e",
+        "zh:4b75e0a259b56d97e66b7d69f3f25bd4cc7be2440c0fe35529f46de7d40a49d3",
+        "zh:694a32519dcca5bd8605d06481d16883d55160d97c1f4039deb13c6ca8de8427",
+        "zh:6a0bcef43c2d9a97aeaaac3c5d1d6728dc2464a51a014f118c691c79029d0903",
+        "zh:6d78fc7c663247ca2a80f276008dcdafece4cac75e2639bbce188c08b796040a",
+        "zh:78f846a505d7b64b67feed1527d4d2b40130dadaf8e3112113685e148f49b156",
+        "zh:881bc969432d3ef6ec70f5a762c3415e037904338579b0a360c6818b74d26e59",
+        "zh:96c1ca80c1d693a3eef80489adb45c076ee8e6878e461d6c29b05388d4b95f48",
+        "zh:9be5fa342272586fc6e319e20f21c0c5c801b05dcf7d59e473ad0882c9ecfa70",
+      ]
+    HCL
+  end
+
+  specify do
+    expect(parser.block).to parse(<<~HCL.chomp)
+      provider "thing" {
+        argument = "value"
+        arguments = [
+          "value",
+          "value",
+        ]
+      }
+    HCL
+  end
+
+  specify do
+    expect(parser.block_body.parse_with_debug(<<~HCL.chomp)).not_to be_nil
+      {
+        argument = "value"
+        arguments = [
+          "value",
+          "value",
+        ]
+      }
+    HCL
+  end
+
+  specify { expect(parser.argument).to parse('argument = "value"') }
+
+  specify do
+    expect(parser.argument).to parse(<<~HCL)
+      arguments = [
+        "a",
+        "b",
+      ]
+    HCL
+  end
+
+  describe '#blocks' do
+    subject { parser.blocks.parse_with_debug(hcl) }
+
+    context 'when parsing multiple multi-line empty blocks' do
+      let(:hcl) do
+        <<~HCL
+          provider "thingy" {
+          }
+
+          provider "other.thingy" {
+          }
+        HCL
+      end
+
+      it 'parses multiple empty blocks' do
+        expect(subject[:blocks]).to match_array([
+          { type: 'provider', name: 'thingy', arguments: [] },
+          { type: 'provider', name: 'other.thingy', arguments: [] },
+        ])
+      end
+    end
+
+    context 'when parsing multiple multi-line blocks with one argument assignment to a string in the first block' do
+      let(:hcl) do
+        <<~HCL
+          provider "thingy" {
+            name = "blah"
+          }
+
+          provider "other.thingy" {
+          }
+        HCL
+      end
+
+      it 'parses multiple empty blocks' do
+        expect(subject[:blocks]).to match_array([
+          { type: 'provider', name: 'thingy', arguments: [{ name: 'name', value: 'blah' }] },
+          { type: 'provider', name: 'other.thingy', arguments: [] },
+        ])
+      end
+    end
+
+    context 'when parsing multiple multi-line blocks with one argument assignment to a string in the second block' do
+      let(:hcl) do
+        <<~HCL
+          provider "thingy" {
+          }
+
+          provider "other.thingy" {
+            name = "blah"
+          }
+        HCL
+      end
+
+      it 'parses multiple empty blocks' do
+        expect(subject[:blocks]).to match_array([
+          { type: 'provider', name: 'thingy', arguments: [] },
+          { type: 'provider', name: 'other.thingy', arguments: [{ name: 'name', value: 'blah' }] },
+        ])
+      end
+    end
+
+    context 'when parsing a blocks with one assignment to an empty array' do
+      let(:hcl) do
+        <<~HCL
+          provider "thingy" {
+            names = [
+            ]
+          }
+        HCL
+      end
+
+      pending 'parses multiple empty blocks' do
+        expect(subject[:blocks]).to match_array([
+          { type: 'provider', name: 'thingy', arguments: [{ name: 'names', values: [] }] },
+        ])
+      end
+    end
+
+    context 'when parsing multiple multi-line blocks with one assignment to a multi-line array' do
+      let(:hcl) do
+        <<~HCL
+          provider "thingy" {
+            names = [
+              "blah"
+            ]
+          }
+
+          provider "other.thingy" {
+          }
+        HCL
+      end
+
+      it 'parses multiple empty blocks' do
+        expect(subject[:blocks]).to match_array([
+          { type: 'provider', name: 'thingy', arguments: [{ name: 'names', values: [{ value: 'blah' }] }] },
+          { type: 'provider', name: 'other.thingy', arguments: [] },
+        ])
+      end
+    end
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 2cd21bf..78ff867 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,6 +1,10 @@
 # frozen_string_literal: true
 
 require "hcl2"
+require "parslet/convenience"
+require "parslet/rig/rspec"
+
+Dir["./spec/support/**/*.rb"].sort.each { |f| require f }
 
 RSpec.configure do |config|
   config.example_status_persistence_file_path = ".rspec_status"
diff --git a/spec/support/files.rb b/spec/support/files.rb
new file mode 100644
index 0000000..81ea2f3
--- /dev/null
+++ b/spec/support/files.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+RSpec.configure do |config|
+  config.include(Module.new do
+    def fixture_file(path)
+      Pathname.new(__FILE__).parent.join('../fixtures', path)
+    end
+
+    def fixture_file_content(path)
+      fixture_file(path).read
+    end
+  end)
+end