FIX: Fix scheduled targeted problem checks (#35696)

Scheduled problem checks with multiple targets are not honouring the
`run_every` configuration.

For checks with multiple targets, all targets are checked in a single
instance of the problem check. However, we have one problem check
tracker per target.

This mismatch results in the `#ready_to_run?` method always creating a
tracker with no target when being checked.

This commit fixes that by:

**Expect checks to operate on a single target.**

This change makes it so that instances of a `ProblemCheck` class are
initialized with a target. So instead of 1-N we now have an N-N
relationship between checks and trackers.

Each instance can access their `target` through an attribute of the same
name.

This also means problem checks are back to returning a singular
`Problem` or `nil`, instead of `[Problem]` or `[]`.

For scheduled checks, this means that `ScheduleProblemChecks` now
enqueues `N` jobs (where `N` is the number of targets) per check instead
of `1` job per check.

**Update existing targeted checks to operate on a single target.**

This is essentially just removing the loop inside the check.

app/jobs/regular/run_problem_check.rb

@@ -12,12 +12,15 @@ module Jobs
     def execute(args)
       retry_count = args[:retry_count].to_i
       identifier = args[:check_identifier].to_sym
+      target = args[:target].to_s
+
+      return if target.blank?
 
       check = ProblemCheck[identifier]
 
-      check.run do |problems|
-        raise RetrySignal if problems.present? && retry_count < check.max_retries
-      end
+      check
+        .new(target)
+        .run { |problem| raise RetrySignal if problem.present? && retry_count < check.max_retries }
     rescue RetrySignal
       Jobs.enqueue_in(
         check.retry_after,

app/jobs/scheduled/run_problem_checks.rb

@@ -10,17 +10,19 @@ module Jobs
     every 10.minutes
 
     def execute(_args)
-      ProblemCheck.scheduled.filter_map do |check|
-        if eligible_for_this_run?(check)
-          Jobs.enqueue(:run_problem_check, check_identifier: check.identifier.to_s)
+      ProblemCheck.scheduled.filter_map do |scheduled_check|
+        scheduled_check.each_target do |target|
+          check = scheduled_check.new(target)
+
+          if check.enabled? && check.ready_to_run?
+            Jobs.enqueue(
+              :run_problem_check,
+              check_identifier: check.identifier.to_s,
+              target: target.to_s,
+            )
+          end
         end
       end
     end
-
-    private
-
-    def eligible_for_this_run?(check)
-      check.enabled? && check.scheduled? && check.ready_to_run?
-    end
   end
 end

app/models/problem_check.rb

@@ -13,7 +13,7 @@ class ProblemCheck
     end
 
     def run_all
-      select(&:enabled?).each(&:run)
+      select(&:enabled?).each { |check| check.each_target { |t| check.new(t).run } }
     end
 
     private
@@ -56,6 +56,11 @@ class ProblemCheck
   #
   config_accessor :inline, default: false, instance_writer: false
 
+  # Used to set up multiple targets for the check. For example, a check that
+  # operates on groups may need to specify which groups to work on.
+  #
+  config_accessor :targets, default: -> { [NO_TARGET] }, instance_writer: false
+
   # Problem check classes need to be registered here in order to be enabled.
   #
   # Note: This list must come after the `config_accessor` declarations.
@@ -114,11 +119,6 @@ class ProblemCheck
     Collection.new(checks.select(&:realtime?))
   end
 
-  def self.tracker(target = NO_TARGET)
-    ProblemCheckTracker[identifier, target]
-  end
-  delegate :tracker, to: :class
-
   def self.identifier
     name.demodulize.underscore.to_sym
   end
@@ -144,85 +144,77 @@ class ProblemCheck
   end
   delegate :inline?, to: :class
 
-  def self.ready_to_run?
-    tracker.ready_to_run?
+  def self.targeted?
+    targets.call != [ProblemCheck::NO_TARGET]
   end
-  delegate :ready_to_run?, to: :class
+  delegate :targeted?, to: :class
 
-  def self.call(data = {})
-    new(data).call
+  def self.each_target(&)
+    targets.call.each(&)
   end
 
-  def self.run(data = {}, &)
-    new(data).run(&)
+  def initialize(target = NO_TARGET)
+    @target = target
   end
 
-  def initialize(data = {})
-    @data = OpenStruct.new(data)
-  end
-
-  attr_reader :data
+  attr_reader :target
 
   def call
     raise NotImplementedError
   end
 
   def run
-    problems = call
+    if targeted? && (target == NO_TARGET || targets.call.exclude?(target))
+      tracker.destroy
+      return
+    end
 
-    yield(problems) if block_given?
+    problem = call
+
+    yield(problem) if block_given?
 
     next_run_at = perform_every&.from_now
 
-    if problems.empty?
-      targets.each { |t| tracker(t).no_problem!(next_run_at:) }
+    if problem.blank?
+      tracker.no_problem!(next_run_at:)
     else
-      problems
-        .uniq(&:target)
-        .each do |problem|
-          problem_translation_data =
-            problem.target.present? ? translation_data(problem.target) : translation_data
-
-          tracker(problem.target).problem!(
-            next_run_at:,
-            details:
-              problem_translation_data.merge(problem.details).merge(base_path: Discourse.base_path),
-          )
-        end
+      tracker.problem!(
+        next_run_at:,
+        details: translation_data.merge(problem.details).merge(base_path: Discourse.base_path),
+      )
     end
+  end
 
-    problems
+  def tracker
+    ProblemCheckTracker[identifier, target]
+  end
+
+  def ready_to_run?
+    tracker.ready_to_run?
   end
 
   private
 
-  def targets
-    [NO_TARGET]
-  end
-
   def problem(target = nil, override_key: nil, override_data: {}, details: {})
     target_identifier = target.kind_of?(ActiveRecord::Base) ? target.id : target
 
-    problem =
-      Problem.new(
-        I18n.t(
-          override_key || translation_key,
-          base_path: Discourse.base_path,
-          **override_data.merge(
-            target.present? ? translation_data(target) : translation_data,
-          ).symbolize_keys,
-        ),
-        priority: self.config.priority,
-        identifier:,
-        target: target_identifier,
-        details:,
-      )
-
-    target.present? ? problem : [problem]
+    Problem.new(
+      I18n.t(
+        override_key || translation_key,
+        base_path: Discourse.base_path,
+        **override_data.merge(
+          target.present? ? translation_data(target) : translation_data,
+        ).symbolize_keys,
+      ),
+      priority: self.config.priority,
+      identifier:,
+      target: target_identifier,
+      details:,
+    )
   end
 
   def no_problem
-    []
+    nil
   end
 
   def translation_key

app/services/problem_check/force_https.rb

@@ -5,7 +5,6 @@ class ProblemCheck::ForceHttps < ProblemCheck
 
   def call
     return no_problem if SiteSetting.force_https
-    return no_problem if !data.check_force_https
 
     problem
   end

app/services/problem_check/group_email_credentials.rb

@@ -9,55 +9,54 @@
 class ProblemCheck::GroupEmailCredentials < ProblemCheck
   self.priority = "high"
   self.perform_every = 30.minutes
+  self.targets = -> do
+    [*Group.with_smtp_configured.pluck(:name), *Group.with_imap_configured.pluck(:name)]
+  end
 
   def call
-    [*smtp_errors, *imap_errors]
+    if group = Group.with_smtp_configured.find_by(name: target)
+      return no_problem if !SiteSetting.enable_smtp
+
+      return(
+        try_validate(group) do
+          EmailSettingsValidator.validate_smtp(
+            host: group.smtp_server,
+            port: group.smtp_port,
+            username: group.email_username,
+            password: group.email_password,
+          )
+        end
+      )
+    end
+
+    if group = Group.with_imap_configured.find_by(name: target)
+      return no_problem if !SiteSetting.enable_imap
+
+      return(
+        try_validate(group) do
+          EmailSettingsValidator.validate_imap(
+            host: group.imap_server,
+            port: group.imap_port,
+            username: group.email_username,
+            password: group.email_password,
+          )
+        end
+      )
+    end
+
+    no_problem
   end
 
   private
 
-  def targets
-    [*Group.with_smtp_configured.pluck(:name), *Group.with_imap_configured.pluck(:name)]
-  end
-
   def translation_data(group)
     { group_name: group.name, group_full_name: group.full_name }
   end
 
-  def smtp_errors
-    return [] if !SiteSetting.enable_smtp
-
-    Group.with_smtp_configured.find_each.filter_map do |group|
-      try_validate(group) do
-        EmailSettingsValidator.validate_smtp(
-          host: group.smtp_server,
-          port: group.smtp_port,
-          username: group.email_username,
-          password: group.email_password,
-        )
-      end
-    end
-  end
-
-  def imap_errors
-    return [] if !SiteSetting.enable_imap
-
-    Group.with_imap_configured.find_each.filter_map do |group|
-      try_validate(group) do
-        EmailSettingsValidator.validate_imap(
-          host: group.imap_server,
-          port: group.imap_port,
-          username: group.email_username,
-          password: group.email_password,
-        )
-      end
-    end
-  end
-
   def try_validate(group, &blk)
     begin
       blk.call
-      nil
+      no_problem
     rescue *EmailSettingsExceptionHandler::EXPECTED_EXCEPTIONS => err
       error_message =
         EmailSettingsExceptionHandler.friendly_exception_message(err, group.smtp_server)
@@ -69,7 +68,7 @@ class ProblemCheck::GroupEmailCredentials < ProblemCheck
         message:
           "Unexpected error when checking SMTP credentials for group #{group.id} (#{group.name}).",
       )
-      nil
+      no_problem
     end
   end
 end

app/services/problem_check/upcoming_change_stable_opted_out.rb

@@ -5,7 +5,19 @@ class ProblemCheck::UpcomingChangeStableOptedOut < ProblemCheck
 
   def call
     return no_problem if !SiteSetting.enable_upcoming_changes
-    status_errors
+
+    # If the site setting is enabled, then the change is opted in, either
+    # manually or automatically, so we skip it.
+    return no_problem if SiteSetting.send(target)
+
+    # Don't care about any changes that are not yet stable, admins can opt
+    # in and out of these without worry.
+    return no_problem if UpcomingChanges.not_yet_stable?(target)
+
+    # At this point, we have an upcoming change that is stable or permanent,
+    # and the site is opted out of it. Admins need to know that the change
+    # will either become permanent or be removed soon.
+    problem(target)
   end
 
   private
@@ -17,23 +29,4 @@ class ProblemCheck::UpcomingChangeStableOptedOut < ProblemCheck
   def targets
     SiteSetting.upcoming_change_site_settings
   end
-
-  def status_errors
-    targets
-      .map do |upcoming_change|
-        # If the site setting is enabled, then the change is opted in, either
-        # manually or automatically, so we skip it.
-        next if SiteSetting.send(upcoming_change)
-
-        # Don't care about any changes that are not yet stable, admins can opt
-        # in and out of these without worry.
-        next if UpcomingChanges.not_yet_stable?(upcoming_change)
-
-        # At this point, we have an upcoming change that is stable or permanent,
-        # and the site is opted out of it. Admins need to know that the change
-        # will either become permanent or be removed soon.
-        problem(upcoming_change)
-      end
-      .compact
-  end
 end

plugins/discourse-ai/app/services/problem_check/ai_credit_hard_limit.rb

@@ -3,32 +3,26 @@
 class ProblemCheck::AiCreditHardLimit < ProblemCheck
   self.priority = "high"
   self.perform_every = 1.hour
+  self.targets = -> do
+    LlmModel.joins(:llm_credit_allocation).where("llm_models.id < 0").pluck("llm_models.id")
+  end
 
   def call
-    return [] if !SiteSetting.discourse_ai_enabled
+    return no_problem if !SiteSetting.discourse_ai_enabled
 
-    problems = []
+    model = LlmModel.where("id < 0").includes(:llm_credit_allocation).find_by(id: target)
 
-    LlmModel
-      .where("id < 0")
-      .includes(:llm_credit_allocation)
-      .find_each do |model|
-        next unless model.llm_credit_allocation
+    return no_problem if model.llm_credit_allocation.blank?
 
-        allocation = model.llm_credit_allocation
+    allocation = model.llm_credit_allocation
 
-        problems << hard_limit_problem(model, allocation) if allocation.hard_limit_reached?
-      end
+    return no_problem if !allocation.hard_limit_reached?
 
-    problems.compact
+    hard_limit_problem(model, allocation)
   end
 
   private
 
-  def targets
-    LlmModel.joins(:llm_credit_allocation).where("llm_models.id < 0").pluck("llm_models.id")
-  end
-
   def hard_limit_problem(model, allocation)
     override_data = {
       model_id: model.id,

plugins/discourse-ai/app/services/problem_check/ai_credit_soft_limit.rb

@@ -3,34 +3,27 @@
 class ProblemCheck::AiCreditSoftLimit < ProblemCheck
   self.priority = "low"
   self.perform_every = 1.hour
+  self.targets = -> do
+    LlmModel.joins(:llm_credit_allocation).where("llm_models.id < 0").pluck("llm_models.id")
+  end
 
   def call
-    return [] if !SiteSetting.discourse_ai_enabled
+    return no_problem if !SiteSetting.discourse_ai_enabled
 
-    problems = []
+    model = LlmModel.where("id < 0").includes(:llm_credit_allocation).find_by(id: target)
 
-    LlmModel
-      .where("id < 0")
-      .includes(:llm_credit_allocation)
-      .find_each do |model|
-        next unless model.llm_credit_allocation
+    return no_problem if model.llm_credit_allocation.blank?
 
-        allocation = model.llm_credit_allocation
+    allocation = model.llm_credit_allocation
 
-        if allocation.soft_limit_reached? && !allocation.hard_limit_reached?
-          problems << soft_limit_problem(model, allocation)
-        end
-      end
+    return no_problem if !allocation.soft_limit_reached?
+    return no_problem if allocation.hard_limit_reached?
 
-    problems.compact
+    soft_limit_problem(model, allocation)
   end
 
   private
 
-  def targets
-    LlmModel.joins(:llm_credit_allocation).where("llm_models.id < 0").pluck("llm_models.id")
-  end
-
   def soft_limit_problem(model, allocation)
     override_data = {
       model_id: model.id,

plugins/discourse-ai/app/services/problem_check/ai_llm_status.rb

@@ -6,31 +6,25 @@ class ProblemCheck::AiLlmStatus < ProblemCheck
   self.max_retries = 2
   self.retry_after = 1.minute
   self.max_blips = 2
+  self.targets = -> { LlmModel.in_use.pluck(:id) }
 
   def call
-    return [] if !SiteSetting.discourse_ai_enabled
+    return no_problem if !SiteSetting.discourse_ai_enabled
 
-    llm_errors
+    model = LlmModel.in_use.find_by(id: target)
+
+    return no_problem if model.blank?
+    return no_problem if model.seeded?
+
+    try_validate(model) { validator.run_test(model) }
   end
 
   private
 
-  def targets
-    LlmModel.in_use.pluck(:id)
-  end
-
-  def llm_errors
-    return [] if !SiteSetting.discourse_ai_enabled
-    LlmModel.in_use.find_each.filter_map do |model|
-      next if model.seeded?
-      try_validate(model) { validator.run_test(model) }
-    end
-  end
-
   def try_validate(model, &blk)
     begin
       blk.call
-      nil
+      no_problem
     rescue => e
       # Skip problem reporting for rate limiting and temporary service issues
       # These are expected to resolve on their own
@@ -38,7 +32,7 @@ class ProblemCheck::AiLlmStatus < ProblemCheck
         Rails.logger.info(
           "AI LLM Status Check: Rate limit detected for model #{model.display_name} (#{model.id}), skipping problem report",
         )
-        return nil
+        return no_problem
       end
 
       # Log transient errors but still return a problem

plugins/discourse-ai/spec/services/problem_check/ai_credit_hard_limit_spec.rb

@@ -1,15 +1,17 @@
 # frozen_string_literal: true
 
 RSpec.describe ProblemCheck::AiCreditHardLimit do
+  subject(:check) { described_class.new(target) }
+
   fab!(:llm_model) { Fabricate(:llm_model, id: -1) }
 
   before { SiteSetting.discourse_ai_enabled = true }
 
   describe "#call" do
-    it "returns no problems when no credit allocations exist" do
-      problems = described_class.new.call
+    let(:target) { llm_model.id }
 
-      expect(problems).to be_empty
+    it "returns no problems when no credit allocations exist" do
+      expect(check).to be_chill_about_it
     end
 
     it "returns no problems when credits are not exhausted" do
@@ -21,9 +23,7 @@ RSpec.describe ProblemCheck::AiCreditHardLimit do
         soft_limit_percentage: 80,
       )
 
-      problems = described_class.new.call
-
-      expect(problems).to be_empty
+      expect(check).to be_chill_about_it
     end
 
     it "returns hard limit problem when credits are exhausted" do
@@ -35,12 +35,7 @@ RSpec.describe ProblemCheck::AiCreditHardLimit do
         soft_limit_percentage: 80,
       )
 
-      problems = described_class.new.call
-
-      expect(problems.size).to eq(1)
-      expect(problems.first.identifier).to eq(:ai_credit_hard_limit)
-      expect(problems.first.priority).to eq("high")
-      expect(problems.first.target).to eq(llm_model.id)
+      expect(check).to have_a_problem.with_priority("high").with_target(llm_model.id)
     end
 
     it "returns hard limit problem when credits are over-exhausted" do
@@ -52,10 +47,7 @@ RSpec.describe ProblemCheck::AiCreditHardLimit do
         soft_limit_percentage: 80,
       )
 
-      problems = described_class.new.call
-
-      expect(problems.size).to eq(1)
-      expect(problems.first.identifier).to eq(:ai_credit_hard_limit)
+      expect(check).to have_a_problem.with_priority("high").with_target(llm_model.id)
     end
 
     it "does not report problem when previous month exceeded limit but current month is new" do
@@ -70,9 +62,9 @@ RSpec.describe ProblemCheck::AiCreditHardLimit do
         )
 
       freeze_time(Time.zone.parse("2025-11-05 10:00:00"))
-      problems = described_class.new.call
 
-      expect(problems).to be_empty
+      expect(check).to be_chill_about_it
+
       allocation.reload
       expect(allocation.monthly_used).to eq(0)
     end
@@ -86,9 +78,7 @@ RSpec.describe ProblemCheck::AiCreditHardLimit do
         monthly_used: 1000,
       )
 
-      problems = described_class.new.call
-
-      expect(problems).to be_empty
+      expect(check).to be_chill_about_it
     end
 
     it "returns no problems when discourse_ai is disabled" do
@@ -100,9 +90,7 @@ RSpec.describe ProblemCheck::AiCreditHardLimit do
         monthly_used: 1000,
       )
 
-      problems = described_class.new.call
-
-      expect(problems).to be_empty
+      expect(check).to be_chill_about_it
     end
   end
 end

plugins/discourse-ai/spec/services/problem_check/ai_credit_soft_limit_spec.rb

@@ -1,15 +1,17 @@
 # frozen_string_literal: true
 
 RSpec.describe ProblemCheck::AiCreditSoftLimit do
+  subject(:check) { described_class.new(target) }
+
   fab!(:llm_model) { Fabricate(:llm_model, id: -1) }
 
   before { SiteSetting.discourse_ai_enabled = true }
 
   describe "#call" do
-    it "returns no problems when no credit allocations exist" do
-      problems = described_class.new.call
+    let(:target) { llm_model.id }
 
-      expect(problems).to be_empty
+    it "returns no problems when no credit allocations exist" do
+      expect(check).to be_chill_about_it
     end
 
     it "returns no problems when credits are not at soft limit" do
@@ -21,9 +23,7 @@ RSpec.describe ProblemCheck::AiCreditSoftLimit do
         soft_limit_percentage: 80,
       )
 
-      problems = described_class.new.call
-
-      expect(problems).to be_empty
+      expect(check).to be_chill_about_it
     end
 
     it "returns soft limit problem when soft limit is reached" do
@@ -35,12 +35,7 @@ RSpec.describe ProblemCheck::AiCreditSoftLimit do
         soft_limit_percentage: 80,
       )
 
-      problems = described_class.new.call
-
-      expect(problems.size).to eq(1)
-      expect(problems.first.identifier).to eq(:ai_credit_soft_limit)
-      expect(problems.first.priority).to eq("low")
-      expect(problems.first.target).to eq(llm_model.id)
+      expect(check).to have_a_problem.with_priority("low").with_target(llm_model.id)
     end
 
     it "does not return soft limit problem when hard limit is reached" do
@@ -52,9 +47,7 @@ RSpec.describe ProblemCheck::AiCreditSoftLimit do
         soft_limit_percentage: 80,
       )
 
-      problems = described_class.new.call
-
-      expect(problems).to be_empty
+      expect(check).to be_chill_about_it
     end
 
     it "does not report problem when previous month exceeded limit but current month is new" do
@@ -69,9 +62,9 @@ RSpec.describe ProblemCheck::AiCreditSoftLimit do
         )
 
       freeze_time(Time.zone.parse("2025-11-05 10:00:00"))
-      problems = described_class.new.call
 
-      expect(problems).to be_empty
+      expect(check).to be_chill_about_it
+
       allocation.reload
       expect(allocation.monthly_used).to eq(0)
     end
@@ -86,9 +79,7 @@ RSpec.describe ProblemCheck::AiCreditSoftLimit do
         soft_limit_percentage: 80,
       )
 
-      problems = described_class.new.call
-
-      expect(problems).to be_empty
+      expect(check).to be_chill_about_it
     end
 
     it "returns no problems when discourse_ai is disabled" do
@@ -101,9 +92,7 @@ RSpec.describe ProblemCheck::AiCreditSoftLimit do
         soft_limit_percentage: 80,
       )
 
-      problems = described_class.new.call
-
-      expect(problems).to be_empty
+      expect(check).to be_chill_about_it
     end
   end
 end

plugins/discourse-ai/spec/services/problem_check/ai_llm_status_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec.describe ProblemCheck::AiLlmStatus do
-  subject(:check) { described_class.new }
+  subject(:check) { described_class.new(target) }
 
   fab!(:llm_model)
   fab!(:ai_persona) { Fabricate(:ai_persona, default_llm_id: llm_model.id) }
@@ -23,6 +23,8 @@ RSpec.describe ProblemCheck::AiLlmStatus do
     { message: "API key error! Please check you have supplied the correct API key." }.to_json
   end
 
+  let(:target) { llm_model.id }
+
   before do
     stub_request(:post, post_url).to_return(status: 200, body: success_response, headers: {})
     assign_fake_provider_to(:ai_default_llm_model)
@@ -50,15 +52,10 @@ RSpec.describe ProblemCheck::AiLlmStatus do
             },
           )
 
-        expect(described_class.new.call.first).to have_attributes(
-          identifier: :ai_llm_status,
-          target: llm_model.id,
-          priority: "high",
-          message: message,
-          details: {
-            error: JSON.parse(error_response)["message"],
-          },
-        )
+        expect(check).to have_a_problem
+          .with_priority("high")
+          .with_target(llm_model.id)
+          .with_message(message)
       end
 
       it "does not return a problem if the LLM models are working" do
@@ -105,25 +102,13 @@ RSpec.describe ProblemCheck::AiLlmStatus do
       it "reports problem for network timeout errors" do
         stub_request(:post, post_url).to_timeout
 
-        problems = described_class.new.call
-        expect(problems.length).to eq(1)
-        expect(problems.first).to have_attributes(
-          identifier: :ai_llm_status,
-          target: llm_model.id,
-          priority: "high",
-        )
+        expect(check).to have_a_problem.with_priority("high").with_target(llm_model.id)
       end
 
       it "reports problem for authentication errors" do
         stub_request(:post, post_url).to_return(status: 401, body: error_response, headers: {})
 
-        problems = described_class.new.call
-        expect(problems.length).to eq(1)
-        expect(problems.first).to have_attributes(
-          identifier: :ai_llm_status,
-          target: llm_model.id,
-          priority: "high",
-        )
+        expect(check).to have_a_problem.with_priority("high").with_target(llm_model.id)
       end
     end
   end

spec/jobs/run_problem_check_spec.rb

@@ -11,14 +11,7 @@ RSpec.describe Jobs::RunProblemCheck do
           self.max_retries = 0
 
           def call
-            [
-              ProblemCheck::Problem.new("Big problem"),
-              ProblemCheck::Problem.new(
-                "Yuge problem",
-                priority: "high",
-                identifier: "config_is_a_mess",
-              ),
-            ]
+            ProblemCheck::Problem.new("Big problem")
           end
         end
 
@@ -29,7 +22,11 @@ RSpec.describe Jobs::RunProblemCheck do
 
     it "updates the problem check tracker" do
       expect {
-        described_class.new.execute(check_identifier: "test_check", retry_count: 0)
+        described_class.new.execute(
+          check_identifier: "test_check",
+          retry_count: 0,
+          target: ProblemCheck::NO_TARGET,
+        )
       }.to change { ProblemCheckTracker.failing.count }.by(1)
     end
   end
@@ -42,7 +39,7 @@ RSpec.describe Jobs::RunProblemCheck do
           self.max_retries = 2
 
           def call
-            [ProblemCheck::Problem.new("Yuge problem")]
+            ProblemCheck::Problem.new("Yuge problem")
           end
         end
 
@@ -53,7 +50,11 @@ RSpec.describe Jobs::RunProblemCheck do
 
     it "does not yet update the problem check tracker" do
       expect {
-        described_class.new.execute(check_identifier: "test_check", retry_count: 1)
+        described_class.new.execute(
+          check_identifier: "test_check",
+          retry_count: 1,
+          target: ProblemCheck::NO_TARGET,
+        )
       }.not_to change { ProblemCheckTracker.where("blips > ?", 0).count }
     end
 
@@ -63,8 +64,11 @@ RSpec.describe Jobs::RunProblemCheck do
         args: {
           check_identifier: "test_check",
           retry_count: 1,
+          target: ProblemCheck::NO_TARGET,
         },
-      ) { described_class.new.execute(check_identifier: "test_check") }
+      ) do
+        described_class.new.execute(check_identifier: "test_check", target: ProblemCheck::NO_TARGET)
+      end
     end
   end
 
@@ -76,7 +80,7 @@ RSpec.describe Jobs::RunProblemCheck do
           self.max_retries = 1
 
           def call
-            [ProblemCheck::Problem.new("Yuge problem")]
+            ProblemCheck::Problem.new("Yuge problem")
           end
         end
 
@@ -87,13 +91,21 @@ RSpec.describe Jobs::RunProblemCheck do
 
     it "updates the problem check tracker" do
       expect {
-        described_class.new.execute(check_identifier: "test_check", retry_count: 1)
+        described_class.new.execute(
+          check_identifier: "test_check",
+          retry_count: 1,
+          target: ProblemCheck::NO_TARGET,
+        )
       }.to change { ProblemCheckTracker.where("blips > ?", 0).count }.by(1)
     end
 
     it "does not schedule a retry" do
       expect_not_enqueued_with(job: :run_problem_check) do
-        described_class.new.execute(check_identifier: "test_check", retry_count: 1)
+        described_class.new.execute(
+          check_identifier: "test_check",
+          retry_count: 1,
+          target: ProblemCheck::NO_TARGET,
+        )
       end
     end
   end

spec/jobs/run_problem_checks_spec.rb

@@ -19,16 +19,28 @@ RSpec.describe Jobs::RunProblemChecks do
         def call = []
       end
 
+    ProblemCheck::MultiTargetCheck =
+      Class.new(ProblemCheck) do
+        self.perform_every = 30.minutes
+        self.targets = -> { %w[foo bar] }
+      end
+
     stub_const(
       ProblemCheck,
       "CORE_PROBLEM_CHECKS",
-      [ProblemCheck::ScheduledCheck, ProblemCheck::NonScheduledCheck, ProblemCheck::DisabledCheck],
+      [
+        ProblemCheck::ScheduledCheck,
+        ProblemCheck::NonScheduledCheck,
+        ProblemCheck::DisabledCheck,
+        ProblemCheck::MultiTargetCheck,
+      ],
       &example
     )
 
     ProblemCheck.send(:remove_const, "ScheduledCheck")
     ProblemCheck.send(:remove_const, "NonScheduledCheck")
     ProblemCheck.send(:remove_const, "DisabledCheck")
+    ProblemCheck.send(:remove_const, "MultiTargetCheck")
   end
 
   context "when a tracker hasn't been created yet" do
@@ -37,6 +49,7 @@ RSpec.describe Jobs::RunProblemChecks do
         job: :run_problem_check,
         args: {
           check_identifier: "scheduled_check",
+          target: ProblemCheck::NO_TARGET,
         },
       ) { described_class.new.execute([]) }
     end
@@ -52,6 +65,7 @@ RSpec.describe Jobs::RunProblemChecks do
         job: :run_problem_check,
         args: {
           check_identifier: "scheduled_check",
+          target: ProblemCheck::NO_TARGET,
         },
       ) { described_class.new.execute([]) }
     end
@@ -110,4 +124,42 @@ RSpec.describe Jobs::RunProblemChecks do
       ) { described_class.new.execute([]) }
     end
   end
+
+  context "when dealing with a multi-target check" do
+    it "schedules one check per target" do
+      expect_enqueued_with(
+        job: :run_problem_check,
+        args: {
+          check_identifier: "multi_target_check",
+          target: "foo",
+        },
+      ) { described_class.new.execute([]) }
+
+      expect_enqueued_with(
+        job: :run_problem_check,
+        args: {
+          check_identifier: "multi_target_check",
+          target: "bar",
+        },
+      ) { described_class.new.execute([]) }
+    end
+
+    it "creates a problem tracker for each target" do
+      expect { described_class.new.execute([]) }.to change {
+        ProblemCheckTracker.where(
+          identifier: "multi_target_check",
+          target: ProblemCheck::MultiTargetCheck.targets.call,
+        ).count
+      }.by(2)
+    end
+
+    it "does not create any no-target tracker" do
+      expect { described_class.new.execute([]) }.not_to change {
+        ProblemCheckTracker.where(
+          identifier: "multi_target_check",
+          target: ProblemCheck::NO_TARGET,
+        ).count
+      }
+    end
+  end
 end

spec/services/problem_check/force_https_spec.rb

@@ -1,14 +1,13 @@
 # frozen_string_literal: true
 
 RSpec.describe ProblemCheck::ForceHttps do
-  subject(:check) { described_class.new(data) }
+  subject(:check) { described_class.new }
 
   describe ".call" do
     before { SiteSetting.stubs(force_https: configured) }
 
     context "when configured to force SSL" do
       let(:configured) { true }
-      let(:data) { { check_force_https: true } }
 
       it { expect(check).to be_chill_about_it }
     end
@@ -16,20 +15,10 @@ RSpec.describe ProblemCheck::ForceHttps do
     context "when not configured to force SSL" do
       let(:configured) { false }
 
-      context "when the request is coming over HTTPS" do
-        let(:data) { { check_force_https: true } }
-
-        it do
-          expect(check).to have_a_problem.with_priority("low").with_message(
-            "Your website is using SSL. But `<a href='/admin/site_settings/category/all_results?filter=force_https'>force_https</a>` is not yet enabled in your site settings.",
-          )
-        end
-      end
-
-      context "when the request is coming over HTTP" do
-        let(:data) { { check_force_https: false } }
-
-        it { expect(check).to be_chill_about_it }
+      it do
+        expect(check).to have_a_problem.with_priority("low").with_message(
+          "Your website is using SSL. But `<a href='/admin/site_settings/category/all_results?filter=force_https'>force_https</a>` is not yet enabled in your site settings.",
+        )
       end
     end
   end

spec/services/problem_check/group_email_credentials_spec.rb

@@ -4,104 +4,96 @@ require "net/smtp"
 require "net/imap"
 
 RSpec.describe ProblemCheck::GroupEmailCredentials do
-  subject(:check) { described_class.new }
+  subject(:check) { described_class.new(target) }
 
-  fab!(:group1, :group)
-  fab!(:group2, :smtp_group)
-  fab!(:group3, :imap_group)
+  fab!(:group1) { Fabricate(:group, smtp_enabled: false, imap_enabled: false) }
+  fab!(:smtp_group) { Fabricate(:smtp_group, name: "smtp_group", imap_enabled: true) }
+  fab!(:imap_group) { Fabricate(:imap_group, name: "imap_group", smtp_enabled: false) }
 
   describe "#call" do
-    it "does nothing if SMTP is disabled for the site" do
-      expect_no_validate_any
-      SiteSetting.enable_smtp = false
-      expect(check).to be_chill_about_it
+    context "when SMTP is disabled for the site" do
+      before { SiteSetting.enable_smtp = false }
+
+      context "with an SMTP-enabled group" do
+        let(:target) { smtp_group.name }
+
+        it "does not report a problem" do
+          expect(check).to be_chill_about_it
+        end
+      end
     end
 
-    context "with smtp and imap enabled for the site" do
+    context "when IMAP is disabled for the site" do
+      before { SiteSetting.enable_imap = false }
+
+      context "with an IMAP-enabled group" do
+        let(:target) { imap_group.name }
+
+        it "does not report a problem" do
+          expect(check).to be_chill_about_it
+        end
+      end
+    end
+
+    context "when SMTP and IMAP are enabled for the site" do
       before do
         SiteSetting.enable_smtp = true
         SiteSetting.enable_imap = true
       end
 
-      it "does nothing if no groups have smtp enabled" do
-        expect_no_validate_any
-        group2.update!(smtp_enabled: false)
-        group3.update!(smtp_enabled: false, imap_enabled: false)
-        expect(check).to be_chill_about_it
+      context "when the group has no SMTP or IMAP enabled" do
+        let(:target) { group1.name }
+
+        it "does not report a problem" do
+          expect(check).to be_chill_about_it
+        end
       end
 
-      it "returns a problem with the group's SMTP settings error" do
-        EmailSettingsValidator
-          .expects(:validate_smtp)
-          .raises(Net::SMTPAuthenticationError.new("bad credentials"))
-          .then
-          .returns(true)
-          .at_least_once
-        EmailSettingsValidator.stubs(:validate_imap).returns(true)
+      context "when SMTP error check fails" do
+        let(:target) { smtp_group.name }
 
-        expect(described_class.new.call).to contain_exactly(
-          have_attributes(
-            identifier: :group_email_credentials,
-            target: group2.id,
-            priority: "high",
-            message:
-              I18n.t(
-                "dashboard.problem.group_email_credentials",
-                base_path: Discourse.base_path,
-                group_name: group2.name,
-                group_full_name: group2.full_name,
-                error:
-                  I18n.t("email_settings.smtp_authentication_error", message: "bad credentials"),
-              ),
-          ),
-        )
+        it "registers a problem with the group's SMTP settings error" do
+          EmailSettingsValidator
+            .expects(:validate_smtp)
+            .raises(Net::SMTPAuthenticationError.new("bad credentials"))
+            .then
+            .returns(true)
+            .at_least_once
+          EmailSettingsValidator.stubs(:validate_imap).returns(true)
+
+          expect(check).to have_a_problem.with_priority("high").with_message(
+            I18n.t(
+              "dashboard.problem.group_email_credentials",
+              base_path: Discourse.base_path,
+              group_name: smtp_group.name,
+              group_full_name: smtp_group.full_name,
+              error: I18n.t("email_settings.smtp_authentication_error", message: "bad credentials"),
+            ),
+          )
+        end
       end
 
-      it "returns an error message and the group ID if the group's IMAP settings error" do
-        EmailSettingsValidator.stubs(:validate_smtp).returns(true)
-        EmailSettingsValidator
-          .expects(:validate_imap)
-          .raises(Net::IMAP::NoResponseError.new(stub(data: stub(text: "Invalid credentials"))))
-          .once
+      context "when IMAP error check fails" do
+        let(:target) { imap_group.name }
 
-        expect(described_class.new.call).to contain_exactly(
-          have_attributes(
-            identifier: :group_email_credentials,
-            target: group3.id,
-            priority: "high",
-            message:
-              I18n.t(
-                "dashboard.problem.group_email_credentials",
-                base_path: Discourse.base_path,
-                group_name: group3.name,
-                group_full_name: group3.full_name,
-                error:
-                  I18n.t("email_settings.imap_authentication_error", message: "bad credentials"),
-              ),
-          ),
-        )
-      end
+        it "registers a problem with the group's IMAP settings error" do
+          EmailSettingsValidator.stubs(:validate_smtp).returns(true)
+          EmailSettingsValidator
+            .expects(:validate_imap)
+            .raises(Net::IMAP::NoResponseError.new(stub(data: stub(text: "Invalid credentials"))))
+            .once
 
-      it "returns no imap errors if imap is disabled for the site" do
-        SiteSetting.enable_imap = false
-        EmailSettingsValidator.stubs(:validate_smtp).returns(true)
-        EmailSettingsValidator.expects(:validate_imap).never
-
-        expect(described_class.new.call).to eq([])
+          expect(check).to have_a_problem.with_priority("high").with_message(
+            I18n.t(
+              "dashboard.problem.group_email_credentials",
+              base_path: Discourse.base_path,
+              group_name: imap_group.name,
+              group_full_name: imap_group.full_name,
+              error: I18n.t("email_settings.imap_authentication_error", message: "bad credentials"),
+            ),
+          )
+        end
       end
     end
   end
-
-  def expect_no_validate_imap
-    EmailSettingsValidator.expects(:validate_imap).never
-  end
-
-  def expect_no_validate_smtp
-    EmailSettingsValidator.expects(:validate_smtp).never
-  end
-
-  def expect_no_validate_any
-    expect_no_validate_smtp
-    expect_no_validate_imap
-  end
 end

spec/services/problem_check/upcoming_change_stable_opted_out_spec.rb

@@ -1,9 +1,11 @@
 # frozen_string_literal: true
 
 RSpec.describe ProblemCheck::UpcomingChangeStableOptedOut do
-  subject(:check) { described_class.new }
+  subject(:check) { described_class.new(target) }
 
   describe ".call" do
+    let(:target) { "enable_upload_debug_mode" }
+
     before do
       mock_upcoming_change_metadata(
         {
@@ -33,7 +35,11 @@ RSpec.describe ProblemCheck::UpcomingChangeStableOptedOut do
       end
 
       context "when upcoming change is stable and not opted in" do
-        it { expect(check).to have_a_problem }
+        it do
+          expect(check).to have_a_problem.with_priority("low").with_target(
+            "enable_upload_debug_mode",
+          )
+        end
       end
 
       context "when upcoming change is not yet stable and not opted in" do
@@ -65,7 +71,11 @@ RSpec.describe ProblemCheck::UpcomingChangeStableOptedOut do
           )
         end
 
-        it { expect(check).to have_a_problem }
+        it do
+          expect(check).to have_a_problem.with_priority("low").with_target(
+            "enable_upload_debug_mode",
+          )
+        end
       end
     end
   end

spec/services/problem_check_spec.rb

@@ -7,6 +7,7 @@ RSpec.describe ProblemCheck do
     InlineCheck = Class.new(described_class) { self.inline = true }
     PluginCheck = Class.new(described_class)
     DisabledCheck = Class.new(described_class) { self.enabled = false }
+    MultiTargetCheck = Class.new(described_class) { self.targets = -> { %w[foo bar] } }
     FailingCheck =
       Class.new(described_class) do
         def call
@@ -31,7 +32,15 @@ RSpec.describe ProblemCheck do
     stub_const(
       described_class,
       "CORE_PROBLEM_CHECKS",
-      [ScheduledCheck, RealtimeCheck, InlineCheck, DisabledCheck, FailingCheck, PassingCheck],
+      [
+        ScheduledCheck,
+        RealtimeCheck,
+        InlineCheck,
+        DisabledCheck,
+        MultiTargetCheck,
+        FailingCheck,
+        PassingCheck,
+      ],
       &example
     )
 
@@ -39,6 +48,7 @@ RSpec.describe ProblemCheck do
     Object.send(:remove_const, RealtimeCheck.name)
     Object.send(:remove_const, InlineCheck.name)
     Object.send(:remove_const, DisabledCheck.name)
+    Object.send(:remove_const, MultiTargetCheck.name)
     Object.send(:remove_const, PluginCheck.name)
     Object.send(:remove_const, FailingCheck.name)
     Object.send(:remove_const, PassingCheck.name)
@@ -49,6 +59,7 @@ RSpec.describe ProblemCheck do
   let(:inline_check) { InlineCheck }
   let(:enabled_check) { RealtimeCheck }
   let(:disabled_check) { DisabledCheck }
+  let(:multi_target_check) { MultiTargetCheck }
   let(:plugin_check) { PluginCheck }
   let(:failing_check) { FailingCheck }
   let(:passing_check) { PassingCheck }
@@ -101,6 +112,11 @@ RSpec.describe ProblemCheck do
     it { expect(disabled_check).not_to be_enabled }
   end
 
+  describe ".targeted?" do
+    it { expect(scheduled_check).not_to be_targeted }
+    it { expect(multi_target_check).to be_targeted }
+  end
+
   describe "plugin problem check registration" do
     before { DiscoursePluginRegistry.register_problem_check(PluginCheck, stub(enabled?: enabled)) }
 
@@ -121,11 +137,32 @@ RSpec.describe ProblemCheck do
 
   describe "#run" do
     context "when check is failing" do
-      it { expect { failing_check.run }.to change { ProblemCheckTracker.failing.count }.by(1) }
+      it { expect { failing_check.new.run }.to change { ProblemCheckTracker.failing.count }.by(1) }
     end
 
     context "when check is passing" do
-      it { expect { passing_check.run }.to change { ProblemCheckTracker.passing.count }.by(1) }
+      it { expect { passing_check.new.run }.to change { ProblemCheckTracker.passing.count }.by(1) }
+    end
+
+    context "when targeted check has a no-target tracker" do
+      before do
+        ProblemCheckTracker.create!(
+          identifier: "multi_target_check",
+          target: ProblemCheck::NO_TARGET,
+        )
+      end
+
+      it "deletes the tracker" do
+        expect { multi_target_check.new.run }.to change { ProblemCheckTracker.count }.by(-1)
+      end
+    end
+
+    context "when targeted check has an outdated target" do
+      before { ProblemCheckTracker.create!(identifier: "multi_target_check", target: "baz") }
+
+      it "deletes the tracker" do
+        expect { multi_target_check.new("baz").run }.to change { ProblemCheckTracker.count }.by(-1)
+      end
     end
   end
 end

spec/support/problem_check_matcher.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec::Matchers.define :be_chill_about_it do
-  match { |service| expect(service.call).to be_empty }
+  match { |service| expect(service.call).to be_blank }
 end
 
 RSpec::Matchers.define :have_a_problem do
@@ -13,24 +13,29 @@ RSpec::Matchers.define :have_a_problem do
     @priority = priority
   end
 
+  chain :with_target do |target|
+    @target = target
+  end
+
   match do |service|
     @result = service.call
 
     aggregate_failures do
-      expect(@result).to include(be_a(ProblemCheck::Problem))
-      expect(@result.first.priority).to(eq(@priority.to_s)) if @priority.present?
-      expect(@result.first.message).to(eq(@message)) if @message.present?
+      expect(@result).to be_a(ProblemCheck::Problem)
+      expect(@result.priority).to(eq(@priority.to_s)) if @priority.present?
+      expect(@result.message).to(eq(@message)) if @message.present?
+      expect(@result.target).to(eq(@target)) if @target.present?
     end
   end
 
   failure_message do |service|
-    if @result.empty?
+    if @result.blank?
       "Expected check to have a problem, but it was chill about it."
-    elsif !@result.all?(ProblemCheck::Problem)
-      "Expected result to contain only instances of `Problem`."
-    elsif @priority.present? && @result.first.priority != @priority
-      "Expected problem to have priority `#{@priority}`, but got priority `#{@result.first.priority}`."
-    elsif @message.present? && @result.first.message != @message
+    elsif !@result.is_a?(ProblemCheck::Problem)
+      "Expected result to must be an instance of `Problem`."
+    elsif @priority.present? && @result.priority != @priority
+      "Expected problem to have priority `#{@priority}`, but got priority `#{@result.priority}`."
+    elsif @message.present? && @result.message != @message
       <<~MESSAGE
         Expected problem to have message:
 
@@ -38,8 +43,10 @@ RSpec::Matchers.define :have_a_problem do
 
         but got message:
 
-          > #{@result.first.message}
+          > #{@result.message}
       MESSAGE
+    elsif @target.present? && @result.target != @target
+      "Expected problem to have target `#{@target}`, but got target `#{@result.target}`."
     end
   end
 end