Bug 1832711 - Update readme and docs for how to use local GV in Fenix

fenix/README.md

@@ -228,13 +228,7 @@ If you wish to use a custom Glean server during local development, you can add a
 - `glean.custom.server.url`
 
 ### GeckoView
-Specify a relative path to your local `mozilla-central` checkout via `dependencySubstitutions.geckoviewTopsrcdir`,
-and optional a path to m-c object directory via `dependencySubstitutions.geckoviewTopobjdir`.
-
-If these are configured, local builds of GeckoView will be used instead of what's configured in Dependencies.kt.
-For more details, see https://firefox-source-docs.mozilla.org/mobile/android/geckoview/contributor/geckoview-quick-start.html#include-geckoview-as-a-dependency
-
-See notes on building successfully in the `android-components` auto-publication section.
+For building with a local checkout of `mozilla-central` see [Substituting Local GeckoView](https://github.com/mozilla-mobile/firefox-android/blob/main/fenix/docs/substituting-local-gv.md)
 
 ## License
 

fenix/docs/substituting-local-gv.md

@@ -0,0 +1,94 @@
+# Substituting local GeckoView
+
+### 1. Manually publish local GeckoView to local Maven
+First, to get the version that we are locally publishing (which will be used in later steps) please add the following:
+
+*geckoview/build.gradle*
+```diff
+diff --git a/mobile/android/geckoview/build.gradle b/mobile/android/geckoview/build.gradle
+index 731026796921b..81cc6782be291 100644
+--- a/mobile/android/geckoview/build.gradle
++++ b/mobile/android/geckoview/build.gradle
+@@ -398,6 +398,7 @@ android.libraryVariants.all { variant ->
+ apply plugin: 'maven-publish'
+
+ version = getVersionNumber()
++println("version = " + version)
+ group = 'org.mozilla.geckoview'
+
+ def getArtifactId() {
+
+```
+
+We can now publish our local GeckoView to our local maven.
+```sh
+./mach build && ./mach gradle \
+ geckoview:publishWithGeckoBinariesDebugPublicationToMavenLocal \
+ exoplayer2:publishDebugPublicationToMavenLocal
+```
+
+:warning: **This needs to be run every time you make changes.** :warning:
+
+You need to copy the version in the logs or run 
+```sh
+./mach build | grep version
+``` 
+(ex. `115.0.20230511122045-SNAPSHOT`)
+
+### 2. Modify Fenix to consume local GV
+Update the build.gradle and Gecko.kt file in Fenix (see the diffs below). Remember to update the GV version with the version you found in step 2!
+
+*fenix/build.gradle*
+```diff 
+diff --git a/fenix/build.gradle b/fenix/build.gradle
+index 6a635a4818..4c8cc28995 100644
+--- a/fenix/build.gradle
++++ b/fenix/build.gradle
+@@ -5,6 +5,7 @@ import org.mozilla.fenix.gradle.tasks.GithubDetailsTask
+ buildscript {
+ // This logic is duplicated in the allprojects block: I don't know how to fix that.
+ repositories {
++ mavenLocal()
+ maven {
+ name "Mozilla Nightly"
+ url "https://nightly.maven.mozilla.org/maven2"
+@@ -90,6 +91,7 @@ plugins {
+ allprojects {
+ // This logic is duplicated in the buildscript block: I don't know how to fix that.
+ repositories {
++ mavenLocal()
+ maven {
+ name "Mozilla Nightly"
+ url "https://nightly.maven.mozilla.org/maven2"
+```
+*Gecko.kt*
+```diff
+diff --git a/android-components/plugins/dependencies/src/main/java/Gecko.kt b/android-components/plugins/dependencies/src/main/java/Gecko.kt
+index bed3fb0161..2d3a19a96e 100644
+--- a/android-components/plugins/dependencies/src/main/java/Gecko.kt
++++ b/android-components/plugins/dependencies/src/main/java/Gecko.kt
+@@ -9,7 +9,7 @@ object Gecko {
+ /**
+ * GeckoView Version.
+ */
+- const val version = "115.0.20230511131014"
++ const val version = "115.0.20230511122045-SNAPSHOT"
+
+ /**
+ * GeckoView channel
+@@ -23,7 +23,7 @@ object Gecko {
+ enum class GeckoChannel(
+ val artifactName: String,
+ ) {
+- NIGHTLY("geckoview-nightly-omni"),
++ NIGHTLY("geckoview-default-omni"),
+ BETA("geckoview-beta-omni"),
+ RELEASE("geckoview-omni"),
+ }
+
+```
+
+### 3. Build fenix with local GV
+Now sync your gradle changes and build! 
+
+An easy way to confirm you are using a local GV is switching your Android Studio project tool window to "Project" and looking in the root directory called "External Libraries" for "GeckoView". You should see something like `Gradle: org.mozilla.geckoview-default-omni:115.0.20230511122045-SNAPSHOT@aar`