Add EquivalentArrayNoDatatypes filter

Author: kpaulisse

doc/advanced-filter.md

@@ -24,7 +24,7 @@ Here is the list of available filters and an explanation of each:
 
 #### Description
 
-When the `AbsentFile` filter is enabled, if any file is `ensure => absent` in the *new* catalog, then changes to any other parameters will be suppressed.
+When the `AbsentFile` filter is enabled, if any file is `ensure => absent` in the _new_ catalog, then changes to any other parameters will be suppressed.
 
 Consider that a file resource is declared as follows in two catalogs:
 
@@ -71,6 +71,25 @@ Wouldn't it be nice if the meaningless information didn't appear, and all you sa
       + absent
 ```
 
+## Equivalent Array (not considering datatypes)
+
+#### Usage
+
+```
+--filters EquivalentArrayNoDatatypes
+```
+
+#### Description
+
+In an array, ignore changes where the old and new arrays are "equivalent" as described below. This is useful when octocatalog-diff is comparing changes between a catalog with stringified values and a catalog with non-stringified values.
+
+The following are considered equivalent when this filter is engaged:
+
+- Stringified integers (`[0, 1]` and `['0', '1']`)
+- Stringified floats (`[0.0, 1.0]` and `['0.0', '1.0']`)
+- Numerically-equal integers and floats (`[0, 1]` and `[0.0, 1.0]`)
+- Symbols and corresponding strings (`[:foo, :bar]` and `[':foo', ':bar']`)
+
 ## JSON
 
 #### Usage
@@ -105,7 +124,7 @@ New: { "notify": [ "Service[foo]" ] }
 This filter will suppress differences for the value of a parameter when:
 
 - The value in one catalog is an object, AND
-- The value in the other catalog is an array containing *only* that same object
+- The value in the other catalog is an array containing _only_ that same object
 
 ## YAML
 

lib/octocatalog-diff/catalog-diff/filter.rb

@@ -1,6 +1,7 @@
 require_relative '../api/v1/diff'
 require_relative 'filter/absent_file'
 require_relative 'filter/compilation_dir'
+require_relative 'filter/equivalent_array_no_datatypes'
 require_relative 'filter/json'
 require_relative 'filter/single_item_array'
 require_relative 'filter/yaml'
@@ -14,7 +15,7 @@ class Filter
       attr_accessor :logger
 
       # List the available filters here (by class name) for use in the validator method.
-      AVAILABLE_FILTERS = %w(AbsentFile CompilationDir JSON SingleItemArray YAML).freeze
+      AVAILABLE_FILTERS = %w(AbsentFile CompilationDir EquivalentArrayNoDatatypes JSON SingleItemArray YAML).freeze
 
       # Public: Determine whether a particular filter exists. This can be used to validate
       # a user-submitted filter.

lib/octocatalog-diff/catalog-diff/filter/equivalent_array_no_datatypes.rb

@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+require_relative '../filter'
+
+module OctocatalogDiff
+  module CatalogDiff
+    class Filter
+      # Filter out changes in parameters where the elements of an array are the
+      # same values but different data types. For example, this would filter out
+      # the following diffs:
+      #   Exec[some command] =>
+      #    parameters =>
+      #      returns =>
+      #        - ["0", "1"]
+      #        + [0, 1]
+      class EquivalentArrayNoDatatypes < OctocatalogDiff::CatalogDiff::Filter
+        # Public: Implement the filter for arrays that have the same elements
+        # but possibly different data types.
+        #
+        # @param diff [OctocatalogDiff::API::V1::Diff] Difference
+        # @param _options [Hash] Additional options (there are none for this filter)
+        # @return [Boolean] true if this should be filtered out, false otherwise
+        def filtered?(diff, _options = {})
+          # Skip additions or removals - focus only on changes
+          return false unless diff.change?
+          old_value = diff.old_value
+          new_value = diff.new_value
+
+          # Skip unless both the old and new values are arrays.
+          return false unless old_value.is_a?(Array) && new_value.is_a?(Array)
+
+          # Avoid generating comparable values if the arrays are a different
+          # size, because there's no possible way that they are equivalent.
+          return false unless old_value.size == new_value.size
+
+          # Generate and then compare the comparable arrays.
+          old_value.map { |x| comparable_value(x) } == new_value.map { |x| comparable_value(x) }
+        end
+
+        # Private: Get a more easily comparable value for an array element.
+        # Integers, floats, and strings that look like integers or floats become
+        # floats, and symbols are converted to string representation.
+        #
+        # @param input [any] Value to convert
+        # @return [any] "Comparable" value
+        def comparable_value(input)
+          # Any string that looks like a number is converted to a float.
+          if input.is_a?(String) && input =~ /\A-?(([0-9]*\.[0-9]+)|([0-9]+))\z/
+            return input.to_f
+          end
+
+          # Any number is converted to a float
+          return input.to_f if input.is_a?(Integer) || input.is_a?(Float)
+
+          # Symbols are converted to ":xxx" strings.
+          return ":#{input}" if input.is_a?(Symbol)
+
+          # Everything else is unconverted.
+          input
+        end
+      end
+    end
+  end
+end

spec/octocatalog-diff/fixtures/catalogs/filter-equivalent-array-1.json

@@ -0,0 +1,55 @@
+{
+  "document_type": "Catalog",
+  "data": {
+    "tags": [
+      "settings"
+    ],
+    "name": "my.rspec.node",
+    "version": "production",
+    "environment": "production",
+    "resources": [
+      {
+        "type": "Exec",
+        "title": "run-my-command 1",
+        "file": "/environments/production/modules/foo/manifests/init.pp",
+        "line": 10,
+        "exported": false,
+        "parameters": {
+          "path": "/usr/bin",
+          "command": "id",
+          "returns": "0"
+        }
+      },
+      {
+        "type": "Exec",
+        "title": "run-my-command 2",
+        "file": "/environments/production/modules/foo/manifests/init.pp",
+        "line": 10,
+        "exported": false,
+        "parameters": {
+          "path": "/usr/bin",
+          "command": "id",
+          "returns": ["0", "1"]
+        }
+      },
+      {
+        "type": "Exec",
+        "title": "run-my-command 3",
+        "file": "/environments/production/modules/foo/manifests/init.pp",
+        "line": 10,
+        "exported": false,
+        "parameters": {
+          "path": "/usr/bin",
+          "command": "id",
+          "returns": ["0", "1", "2"]
+        }
+      }
+    ],
+    "classes": [
+      "settings"
+    ]
+  },
+  "metadata": {
+    "api_version": 1
+  }
+}

spec/octocatalog-diff/fixtures/catalogs/filter-equivalent-array-2.json

@@ -0,0 +1,55 @@
+{
+  "document_type": "Catalog",
+  "data": {
+    "tags": [
+      "settings"
+    ],
+    "name": "my.rspec.node",
+    "version": "production",
+    "environment": "production",
+    "resources": [
+      {
+        "type": "Exec",
+        "title": "run-my-command 1",
+        "file": "/environments/production/modules/foo/manifests/init.pp",
+        "line": 10,
+        "exported": false,
+        "parameters": {
+          "path": "/usr/bin",
+          "command": "id",
+          "returns": 0
+        }
+      },
+      {
+        "type": "Exec",
+        "title": "run-my-command 2",
+        "file": "/environments/production/modules/foo/manifests/init.pp",
+        "line": 10,
+        "exported": false,
+        "parameters": {
+          "path": "/usr/bin",
+          "command": "id",
+          "returns": [0, 1]
+        }
+      },
+      {
+        "type": "Exec",
+        "title": "run-my-command 3",
+        "file": "/environments/production/modules/foo/manifests/init.pp",
+        "line": 10,
+        "exported": false,
+        "parameters": {
+          "path": "/usr/bin",
+          "command": "id",
+          "returns": [0, 1, 2, 3]
+        }
+      }
+    ],
+    "classes": [
+      "settings"
+    ]
+  },
+  "metadata": {
+    "api_version": 1
+  }
+}

spec/octocatalog-diff/integration/filter_equivalent_array_no_datatypes_spec.rb

@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+require_relative 'integration_helper'
+
+describe 'equivalent array no datatypes filter integration' do
+  context 'with default behavior' do
+    before(:all) do
+      @result = OctocatalogDiff::Integration.integration(
+        spec_catalog_old: 'filter-equivalent-array-1.json',
+        spec_catalog_new: 'filter-equivalent-array-2.json'
+      )
+    end
+
+    it 'should succeed' do
+      expect(@result[:exitcode]).not_to eq(-1), "Internal error: #{@result[:exception]}\n#{@result[:logs]}"
+      expect(@result[:exitcode]).to eq(2), "Runtime error: #{@result[:logs]}"
+    end
+
+    it 'should not suppress equivalent-but-for-data-type arrays' do
+      diffs = OctocatalogDiff::Spec.remove_file_and_line(@result[:diffs])
+      expect(diffs.size).to eq(3), diffs.inspect
+      expect(diffs[0][1..3]).to eq(["Exec\frun-my-command 1\fparameters\freturns", '0'.inspect, 0])
+      expect(diffs[1][1..3]).to eq(["Exec\frun-my-command 2\fparameters\freturns", %w[0 1], [0, 1]])
+      expect(diffs[2][1..3]).to eq(["Exec\frun-my-command 3\fparameters\freturns", %w[0 1 2], [0, 1, 2, 3]])
+    end
+  end
+
+  context 'with equivalent array no datatypes filter engaged' do
+    before(:all) do
+      @result = OctocatalogDiff::Integration.integration(
+        spec_catalog_old: 'filter-equivalent-array-1.json',
+        spec_catalog_new: 'filter-equivalent-array-2.json',
+        argv: ['--filters', 'EquivalentArrayNoDatatypes']
+      )
+    end
+
+    it 'should succeed' do
+      expect(@result[:exitcode]).not_to eq(-1), "Internal error: #{@result[:exception]}\n#{@result[:logs]}"
+      expect(@result[:exitcode]).to eq(2), "Runtime error: #{@result[:logs]}"
+    end
+
+    it 'should suppress equivalent-but-for-data-type arrays' do
+      diffs = OctocatalogDiff::Spec.remove_file_and_line(@result[:diffs])
+      expect(diffs.size).to eq(2), diffs.inspect
+      # '0' => 0 is not suppressed because it's not an array
+      expect(diffs[0][1..3]).to eq(["Exec\frun-my-command 1\fparameters\freturns", '0'.inspect, 0])
+      # %w[0 1] => [0, 1] is suppressed
+      # %w[0 1 2] => [0, 1, 2, 3] is not suppressed because it's not equivalent
+      expect(diffs[1][1..3]).to eq(["Exec\frun-my-command 3\fparameters\freturns", %w[0 1 2], [0, 1, 2, 3]])
+    end
+  end
+end