Hide delete changes in admin lambda output

Author: jwils

elasticgraph-admin_lambda/lib/elastic_graph/admin_lambda/lambda_function.rb

@@ -20,7 +20,10 @@ def initialize
 
       def handle_request(event:, context:)
         # @type var event: ::Hash[::String, untyped]
-        rake_output = RakeAdapter.run_rake(event.fetch("argv"))
+        rake_output = RakeAdapter.run_rake(
+          event.fetch("argv"),
+          hide_delete_changes: event.fetch("hide_delete_changes", false)
+        )
 
         # Log the output of the rake task. We also want to return it so that when we invoke
         # a lambda rake task from the terminal we can print the output there.

elasticgraph-admin_lambda/lib/elastic_graph/admin_lambda/rake_adapter.rb

@@ -14,17 +14,24 @@ module AdminLambda
     # @private
     class RakeAdapter
       RAKEFILE = File.expand_path("../Rakefile", __FILE__)
+      DELETE_CHANGE_PATTERN = /\A- [^:\n]+: /
 
-      def self.run_rake(argv)
-        capture_output do
+      def self.run_rake(argv, hide_delete_changes: false)
+        rake_output = capture_output do
           # We need to instantiate a new application on each invocation, because Rake is normally
           # designed to run once and exit. It keeps track of tasks that have already run and will
           # no-op when you try to run a task a 2nd or 3rd time. Using a new application instance
           # each time avoids this issue.
           ::Rake.with_application(Application.new) do |application|
             application.run(argv)
           end
-        end
+        end || ""
+
+        hide_delete_changes ? filter_delete_changes(rake_output) : rake_output
+      end
+
+      def self.filter_delete_changes(rake_output)
+        rake_output.lines.reject { |line| line.match?(DELETE_CHANGE_PATTERN) }.join
       end
 
       # Captures stdout/stderr into a string so we can return it from the lambda.

elasticgraph-admin_lambda/sig/elastic_graph/admin_lambda/rake_adapter.rbs

@@ -2,8 +2,10 @@ module ElasticGraph
   module AdminLambda
     class RakeAdapter
       RAKEFILE: ::String
+      DELETE_CHANGE_PATTERN: ::Regexp
 
-      def self.run_rake: (::Array[::String]) -> ::String?
+      def self.run_rake: (::Array[::String], ?hide_delete_changes: bool) -> ::String
+      def self.filter_delete_changes: (::String) -> ::String
       def self.capture_output: () { () -> void } -> ::String?
 
       class Application < ::Rake::Application

elasticgraph-admin_lambda/spec/integration/elastic_graph/admin_lambda/rake_adapter_spec.rb

@@ -42,6 +42,23 @@ module AdminLambda
         end
       end
 
+      it "can filter delete changes from the rake output" do
+        allow(RakeAdapter).to receive(:capture_output).and_return(<<~OUTPUT)
+          Updated mappings for index `widgets`:
+          - properties.name: {"type"=>"keyword"}
+          + properties.description: {"type"=>"text"}
+          ~ settings.index.refresh_interval: `"1s"` => `"5s"`
+          - this is a regular line, not a diff
+        OUTPUT
+
+        expect(RakeAdapter.run_rake(["clusters:configure:dry_run"], hide_delete_changes: true)).to eq(<<~OUTPUT)
+          Updated mappings for index `widgets`:
+          + properties.description: {"type"=>"text"}
+          ~ settings.index.refresh_interval: `"1s"` => `"5s"`
+          - this is a regular line, not a diff
+        OUTPUT
+      end
+
       def rake_tasks_printed_to(string)
         string
           .split("\n")

elasticgraph-admin_lambda/spec/unit/elastic_graph/admin_lambda/lambda_function_spec.rb

@@ -22,4 +22,23 @@
       }.to output(a_string_including("rake clusters:configure:dry_run")).to_stdout_from_any_process
     end
   end
+
+  it "can hide delete changes from the rake output" do
+    expect_loading_lambda_to_define_constant(
+      lambda: "elastic_graph/admin_lambda/lambda_function.rb",
+      const: :HandleAdminRequest
+    ) do |lambda_function|
+      allow(ElasticGraph::AdminLambda::RakeAdapter).to receive(:run_rake)
+        .with(["clusters:configure:dry_run"], hide_delete_changes: true)
+        .and_return("+ properties.description: {\"type\"=>\"text\"}\n")
+
+      expect {
+        response = lambda_function.handle_request(
+          event: {"argv" => ["clusters:configure:dry_run"], "hide_delete_changes" => true},
+          context: {}
+        )
+        expect(response["rake_output"]).to eq("+ properties.description: {\"type\"=>\"text\"}\n")
+      }.to output(a_string_including("+ properties.description: {\"type\"=>\"text\"}\n")).to_stdout_from_any_process
+    end
+  end
 end