Updates Sentry.Sources to support multiple source code root paths

Before the changes in this commit Sentry.Sources only looked for source
code files in one root path, the `:root_source_code_path`.

With the changes in this commit this module will now be able to look for
source code in multiple paths. The paths can be configured in the
`:root_source_code_paths` config key.

This change is specially important for umbrella applications [1], that
have their code nested in the `apps` path. If we don't specify the root
path for each individual application (which isn't possible without the
changes in this commit), and instead just use `File.cwd!()` as the root
path, the source code files of each umbrella app will be loaded with
`apps/<app name>` prefix in their name. This is a problem because these
names will never match the file names in the stacktrace, which means
that Sentry won't be able to attach source code context.

To avoid a configuration breaking change, the changes in this commit
still support the `:root_source_code_path` configuration key, but "soft
deprecate" it by removing it from documentation. This config key should
be fully deprecated in the next major Sentry release.

[1] https://elixir-lang.org/getting-started/mix-otp/dependencies-and-umbrella-projects.html

Author: jbernardo95

README.md

@@ -139,7 +139,7 @@ config :sentry,
   environment_name: Mix.env(),
   included_environments: [:prod],
   enable_source_code_context: true,
-  root_source_code_path: File.cwd!()
+  root_source_code_paths: [File.cwd!()]
 ```
 
 The `environment_name` and `included_environments` work together to determine
@@ -169,7 +169,7 @@ The full range of options is the following:
 | `in_app_module_whitelist` | False | `[]` | |
 | `report_deps` | False | True | Will attempt to load Mix dependencies at compile time to report alongside events |
 | `enable_source_code_context` | False | False | |
-| `root_source_code_path` | Required if `enable_source_code_context` is enabled | | Should generally be set to `File.cwd!()`|
+| `root_source_code_paths` | Required if `enable_source_code_context` is enabled | | Should usually be set to `[File.cwd!()]`. For umbrella applications you should list all your applications paths in this list (e.g. `["#{File.cwd!()}/apps/app_1", "#{File.cwd!()}/apps/app_2"]`. |
 | `context_lines` | False  | 3 | |
 | `source_code_exclude_patterns` | False  | `[~r"/_build/", ~r"/deps/", ~r"/priv/"]` | |
 | `source_code_path_pattern` | False  | `"**/*.ex"` | |

config/config.exs

@@ -5,6 +5,6 @@ config :sentry,
   environment_name: :dev,
   tags: %{},
   enable_source_code_context: true,
-  root_source_code_path: File.cwd!()
+  root_source_code_paths: [File.cwd!()]
 
 import_config "#{Mix.env()}.exs"

lib/sentry/config.ex

@@ -77,13 +77,27 @@ defmodule Sentry.Config do
     get_config(:enable_source_code_context, default: false, check_dsn: false)
   end
 
-  def root_source_code_path do
+  # :root_source_code_path (single path) was replaced by :root_source_code_paths (list of
+  # paths).
+  #
+  # In order for this to not be a breaking change we still accept the old
+  # :root_source_code_path as a fallback.
+  #
+  # We should deprecate this the :root_source_code_path completely in the next major
+  # release.
+  def root_source_code_paths do
+    paths = get_config(:root_source_code_paths)
     path = get_config(:root_source_code_path)
 
-    if path do
-      path
-    else
-      raise ArgumentError.exception(":root_source_code_path must be configured")
+    cond do
+      not is_nil(paths) ->
+        paths
+
+      not is_nil(path) ->
+        [path]
+
+      true ->
+        raise ArgumentError.exception(":root_source_code_paths must be configured")
     end
   end
 

lib/sentry/sources.ex

@@ -8,13 +8,14 @@ defmodule Sentry.Sources do
 
   ### Configuration
   There is configuration required to set up this functionality.  The options
-  include `:enable_source_code_context`, `:root_source_code_path`, `:context_lines`,
+  include `:enable_source_code_context`, `:root_source_code_paths`, `:context_lines`,
   `:source_code_exclude_patterns`, and `:source_code_path_pattern`.
 
   * `:enable_source_code_context` - when `true`, enables reporting source code
     alongside exceptions.
-  * `:root_source_code_path` - The path from which to start recursively reading files from.
-    Should usually be set to `File.cwd!()`.
+  * `:root_source_code_paths` - List of paths from which to start recursively reading files from.
+    Should usually be set to `[File.cwd!()]`. For umbrella applications you should list all your
+    applications paths in this list (e.g. `["#{File.cwd!()}/apps/app_1", "#{File.cwd!()}/apps/app_2"]`.
   * `:context_lines` - The number of lines of source code before and after the line that
     caused the exception to be included.  Defaults to `3`.
   * `:source_code_exclude_patterns` - a list of Regex expressions used to exclude file paths that
@@ -28,7 +29,7 @@ defmodule Sentry.Sources do
       config :sentry,
         dsn: "https://public:[email protected]/1",
         enable_source_code_context: true,
-        root_source_code_path: File.cwd!(),
+        root_source_code_path: [File.cwd!()],
         context_lines: 5
 
   ### Source code storage
@@ -64,18 +65,20 @@ defmodule Sentry.Sources do
   @type source_map :: %{String.t() => file_map}
 
   def load_files do
-    root_path = Config.root_source_code_path()
+    root_paths = Config.root_source_code_paths()
     path_pattern = Config.source_code_path_pattern()
     exclude_patterns = Config.source_code_exclude_patterns()
 
-    Path.join(root_path, path_pattern)
-    |> Path.wildcard()
-    |> exclude_files(exclude_patterns)
-    |> Enum.reduce(%{}, fn path, acc ->
-      key = Path.relative_to(path, root_path)
-      value = source_to_lines(File.read!(path))
+    Enum.reduce(root_paths, %{}, fn root_path, acc1 ->
+      Path.join(root_path, path_pattern)
+      |> Path.wildcard()
+      |> exclude_files(exclude_patterns)
+      |> Enum.reduce(acc1, fn path, acc2 ->
+        key = Path.relative_to(path, root_path)
+        value = source_to_lines(File.read!(path))
 
-      Map.put(acc, key, value)
+        Map.put(acc2, key, value)
+      end)
     end)
   end
 

test/sources_test.exs

@@ -3,6 +3,32 @@ defmodule Sentry.SourcesTest do
   use Plug.Test
   import Sentry.TestEnvironmentHelper
 
+  describe "load_files/0" do
+    test "loads files" do
+      Application.put_env(:sentry, :root_source_code_paths, [
+        File.cwd!() <> "/test/support/example-umbrella-app/apps/app_a",
+        File.cwd!() <> "/test/support/example-umbrella-app/apps/app_b"
+      ])
+
+      assert %{
+               "lib/module_a.ex" => %{
+                 1 => "defmodule ModuleA do",
+                 2 => "  def test do",
+                 3 => "    \"test a\"",
+                 4 => "  end",
+                 5 => "end"
+               },
+               "lib/module_b.ex" => %{
+                 1 => "defmodule ModuleB do",
+                 2 => "  def test do",
+                 3 => "    \"test b\"",
+                 4 => "  end",
+                 5 => "end"
+               }
+             } = Sentry.Sources.load_files()
+    end
+  end
+
   test "exception makes call to Sentry API" do
     correct_context = %{
       "context_line" => "    raise RuntimeError, \"Error\"",

test/support/example-umbrella-app/apps/app_a/lib/module_a.ex

@@ -0,0 +1,5 @@
+defmodule ModuleA do
+  def test do
+    "test a"
+  end
+end

test/support/example-umbrella-app/apps/app_b/lib/module_b.ex

@@ -0,0 +1,5 @@
+defmodule ModuleB do
+  def test do
+    "test b"
+  end
+end