From 0e3593fc5d839e4a74523f07e885b761ee19e662 Mon Sep 17 00:00:00 2001
From: Daniel Wagner-Hall <dwagnerhall@apple.com>
Date: Fri, 17 Dec 2021 10:40:39 +0000
Subject: [PATCH] Define remote repositories with maybe (#1071)

This allows individual repositories to be overridden by binding
replacement repositories as long as the same name is used.

The names we give to repositories are not currently part of the API
contract of crate_universe, but this can still be useful.
---
 crate_universe/src/renderer.rs                    | 15 +++++++++++----
 crate_universe/src/templates/defs.bzl.template    |  4 +++-
 .../templates/partials/git_repository.template    |  3 ++-
 .../src/templates/partials/http_archive.template  |  3 ++-
 4 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/crate_universe/src/renderer.rs b/crate_universe/src/renderer.rs
index ff94b896bf..52fe173d12 100644
--- a/crate_universe/src/renderer.rs
+++ b/crate_universe/src/renderer.rs
@@ -578,9 +578,11 @@ mod tests {
 
         let expected_repository_rule = indoc! { r#"
             load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+            load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
 
             def pinned_rust_install():
-                http_archive(
+                maybe(
+                    http_archive,
                     name = "rule_prefix__lazy_static__1_4_0",
                     build_file = Label("//:BUILD.lazy_static-1.4.0.bazel"),
                     sha256 = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646",
@@ -608,9 +610,11 @@ mod tests {
 
         let expected_repository_rule = indoc! { r#"
             load("@bazel_tools//tools/build_defs/repo:git.bzl", "new_git_repository")
+            load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
 
             def pinned_rust_install():
-                new_git_repository(
+                maybe(
+                    new_git_repository,
                     name = "rule_prefix__lazy_static__1_4_0",
                     strip_prefix = "",
                     build_file = Label("//:BUILD.lazy_static-1.4.0.bazel"),
@@ -650,9 +654,11 @@ mod tests {
         let expected_repository_rule = indoc! { r#"
             load("@bazel_tools//tools/build_defs/repo:git.bzl", "new_git_repository")
             load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+            load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
 
             def pinned_rust_install():
-                new_git_repository(
+                maybe(
+                    new_git_repository,
                     name = "rule_prefix__lazy_static__1_4_0",
                     strip_prefix = "",
                     build_file = Label("//:BUILD.lazy_static-1.4.0.bazel"),
@@ -661,7 +667,8 @@ mod tests {
                     commit = "421669662b35fcb455f2902daed2e20bbbba79b6",
                 )
 
-                http_archive(
+                maybe(
+                    http_archive,
                     name = "rule_prefix__maplit__1_0_2",
                     build_file = Label("//:BUILD.maplit-1.0.2.bazel"),
                     sha256 = "3e2e65a1a2e43cfcb47a895c4c8b10d1f4a61097f9f254f183aee60cad9c651d",
diff --git a/crate_universe/src/templates/defs.bzl.template b/crate_universe/src/templates/defs.bzl.template
index c28572e9f8..b926b75762 100644
--- a/crate_universe/src/templates/defs.bzl.template
+++ b/crate_universe/src/templates/defs.bzl.template
@@ -10,7 +10,9 @@ load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 {% break %}
 {%- endif %}
 {%- endfor %}
-{%- if crates %}
+{%- if crates -%}
+load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
+
 {% endif -%}
 def pinned_rust_install():
 {%- if not crates %}
diff --git a/crate_universe/src/templates/partials/git_repository.template b/crate_universe/src/templates/partials/git_repository.template
index b3ea7ec728..f4b6279279 100644
--- a/crate_universe/src/templates/partials/git_repository.template
+++ b/crate_universe/src/templates/partials/git_repository.template
@@ -1,4 +1,5 @@
-    new_git_repository(
+    maybe(
+        new_git_repository,
         name = "{{ repository_name }}",
         strip_prefix = "{{ repo.path_to_crate_root }}",
         build_file = Label("//:BUILD.{{crate.pkg_name}}-{{crate.pkg_version}}.bazel"),
diff --git a/crate_universe/src/templates/partials/http_archive.template b/crate_universe/src/templates/partials/http_archive.template
index c792321803..b15062dcef 100644
--- a/crate_universe/src/templates/partials/http_archive.template
+++ b/crate_universe/src/templates/partials/http_archive.template
@@ -1,4 +1,5 @@
-    http_archive(
+    maybe(
+        http_archive,
         name = "{{repository_name}}",
         build_file = Label("//:BUILD.{{crate.pkg_name}}-{{crate.pkg_version}}.bazel"),
         {%- if crate.sha256 %}