From 34a510852717e854e5fd206f3e2185d34bfed144 Mon Sep 17 00:00:00 2001
From: Nathan Youngman <nathan.youngman@copiawealthstudios.com>
Date: Wed, 19 Jun 2024 15:45:51 -0600
Subject: [PATCH] Resolve Dialyzer errors on Elixir 1.16 (#643)

---
 .github/workflows/test.yml | 72 ++++++++++++++++++++++++++++++++------
 lib/tesla/multipart.ex     |  8 ++++-
 mix.exs                    |  2 +-
 3 files changed, 70 insertions(+), 12 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 698ceaf1..e5e69b8b 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -10,16 +10,16 @@ jobs:
     strategy:
       matrix:
         include:
-          - otp: '25.3.2.12'
-            elixir: '1.15.8'
+          - elixir: '1.15.8'
+            otp: '25.3.2.12'
             experimental: false
             lint: false
-          - otp: '26.2.5'
-            elixir: '1.16.3'
+          - elixir: '1.16.3'
+            otp: '26.2.5'
             experimental: true
             lint: true
-          - otp: '27.0'
-            elixir: '1.17.1'
+          - elixir: '1.17.1'
+            otp: '27.0'
             experimental: true
             lint: false
     steps:
@@ -32,11 +32,13 @@ jobs:
         version-type: strict
     - name: Restore dependencies cache
       uses: actions/cache@v4
+      id: cache
       with:
         path: deps
-        key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
-        restore-keys: ${{ runner.os }}-mix-
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-mix-${{ hashFiles('**/mix.lock') }}
+        restore-keys: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-mix-
     - name: Install Dependencies
+      if: steps.cache.outputs.cache-hit != 'true'
       env:
         MIX_ENV: test
       run: |
@@ -63,10 +65,11 @@ jobs:
         version-type: strict
     - name: Restore dependencies cache
       uses: actions/cache@v4
+      id: cache
       with:
         path: deps
-        key: ${{ runner.os }}-mix-${{ hashFiles('test/lockfiles/gun1.lock') }}
-        restore-keys: ${{ runner.os }}-mix-
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-mix-gun-${{ hashFiles('test/lockfiles/gun1.lock') }}
+        restore-keys: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-mix-gun-
     - name: Install Dependencies
       env:
         MIX_ENV: test
@@ -79,3 +82,52 @@ jobs:
       env:
         LOCKFILE: gun1
       run: mix test test/tesla/adapter/gun_test.exs --trace
+
+  dialyzer:
+    runs-on: ubuntu-latest
+    name: Dialyzer
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Elixir
+      uses: erlef/setup-beam@v1
+      with:
+        elixir-version: '1.16.3'
+        otp-version: '26.2.5'
+        version-type: strict
+    - name: Restore dependencies cache
+      uses: actions/cache@v4
+      id: cache
+      with:
+        path: |
+          deps
+          _build
+          dialyzer
+        key: ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-dialyzer-${{ hashFiles('**/mix.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-dialyzer-
+    - name: Install Dependencies
+      if: steps.cache.outputs.cache-hit != 'true'
+      env:
+        MIX_ENV: test
+      run: |
+        mix local.rebar --force
+        mix local.hex --force
+        mix deps.get
+    # Doesn't cache PLTs based on mix.lock hash, as Dialyzer can incrementally update even old ones
+    # Cache key based on Elixir & Erlang version.
+    - name: Restore PLT cache
+      uses: actions/cache@v2
+      id: plt_cache
+      with:
+        key: |
+          ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-plt
+        restore-keys: |
+          ${{ runner.os }}-${{ steps.beam.outputs.elixir-version }}-${{ steps.beam.outputs.otp-version }}-plt
+        path: |
+          priv/plts
+    # Create PLTs if no cache was found
+    - name: Create PLTs
+      if: steps.plt_cache.outputs.cache-hit != 'true'
+      run: mix dialyzer --plt
+    - name: Run dialyzer
+      run: mix dialyzer --format github
diff --git a/lib/tesla/multipart.ex b/lib/tesla/multipart.ex
index be8673dc..cce7fc9e 100644
--- a/lib/tesla/multipart.ex
+++ b/lib/tesla/multipart.ex
@@ -103,7 +103,7 @@ defmodule Tesla.Multipart do
         false -> headers
       end
 
-    data = File.stream!(path, [], 2048)
+    data = stream_file!(path, 2048)
     add_file_content(mp, data, filename, opts ++ [headers: headers])
   end
 
@@ -194,4 +194,10 @@ defmodule Tesla.Multipart do
   defp assert_part_value!(val) do
     raise(ArgumentError, "#{inspect(val)} is not a supported multipart value.")
   end
+
+  if Version.compare(System.version(), "1.16.0") in [:gt, :eq] do
+    defp stream_file!(path, bytes), do: File.stream!(path, bytes)
+  else
+    defp stream_file!(path, bytes), do: File.stream!(path, [], bytes)
+  end
 end
diff --git a/mix.exs b/mix.exs
index cdf01a37..9dca78b0 100644
--- a/mix.exs
+++ b/mix.exs
@@ -18,7 +18,7 @@ defmodule Tesla.Mixfile do
       dialyzer: [
         plt_core_path: "_build/#{Mix.env()}",
         plt_add_apps: [:mix, :inets, :idna, :ssl_verify_fun, :ex_unit],
-        plt_add_deps: :project
+        plt_add_deps: :apps_direct
       ],
       docs: docs(),
       preferred_cli_env: [coveralls: :test, "coveralls.html": :test]