Add forc feature for overriding packages in the package graph, akin to cargo's [patch] feature (#1836)

Author: kayagokalp

docs/src/forc/manifest_reference.md

@@ -17,6 +17,8 @@ The `Forc.toml` (the _manifest_ file) is a compulsory file for each package and
 
 * [`[build-profiles]`](#the-build-profiles--section) - Defines the build profiles.
 
+* [`[patch]`](#the-patch-section) - Defines the patches.
+
 ## The `[project]` section
 
 An example `Forc.toml` is shown below. Under `[project]` the following fields are optional:
@@ -99,3 +101,47 @@ Note that providing the corresponding cli options (like `--print-finalized-asm`)
 * print-intermediate-asm - false
 * print-ir - false
 * silent - false
+
+## The `[patch]` section
+
+The [patch] section of `Forc.toml` can be used to override dependencies with other copies. The example provided below patches <https://github.com/fuellabs/sway> source with master branch of the same repo.
+
+```toml
+[project]
+authors = ["user"]
+entry = "main.sw"
+organization = "Fuel_Labs"
+license = "Apache-2.0"
+name = "wallet_contract"
+
+[dependencies]
+
+[patch.'https://github.com/fuellabs/sway']
+std = { git = "https://github.com/fuellabs/sway", branch = "test" }
+```
+
+In the example above, `std` is patched with the `test` branch from `std` repo. You can also patch git dependencies with dependencies defined with a path.
+
+```toml
+[patch.'https://github.com/fuellabs/sway']
+std = { path = "/path/to/local_std_version" }
+```
+
+Just like `std` or `core` you can also patch dependencies you declared with a git repo.
+
+```toml
+[project]
+authors = ["user"]
+entry = "main.sw"
+organization = "Fuel_Labs"
+license = "Apache-2.0"
+name = "wallet_contract"
+
+[dependencies]
+foo = { git = "https://github.com/foo/foo", branch = "master" }
+
+[patch.'https://github.com/foo']
+foo = { git = "https://github.com/foo/foo", branch = "test" }
+```
+
+Note that each key after the `[patch]` is a URL of the source that is being patched.

forc-pkg/src/manifest.rs

@@ -11,6 +11,8 @@ use std::{
 use sway_core::{parse, TreeType};
 use sway_utils::constants;
 
+type PatchMap = BTreeMap<String, Dependency>;
+
 /// A [Manifest] that was deserialized from a file at a particular path.
 #[derive(Debug)]
 pub struct ManifestFile {
@@ -27,6 +29,7 @@ pub struct Manifest {
     pub project: Project,
     pub network: Option<Network>,
     pub dependencies: Option<BTreeMap<String, Dependency>>,
+    pub patch: Option<BTreeMap<String, PatchMap>>,
     build_profile: Option<BTreeMap<String, BuildProfile>>,
 }
 
@@ -271,6 +274,14 @@ impl Manifest {
         })
     }
 
+    /// Produce an iterator yielding all listed patches.
+    pub fn patches(&self) -> impl Iterator<Item = (&String, &PatchMap)> {
+        self.patch
+            .as_ref()
+            .into_iter()
+            .flat_map(|patches| patches.iter())
+    }
+
     /// Check for the `core` and `std` packages under `[dependencies]`. If both are missing, add
     /// `std` implicitly.
     ///

forc-pkg/src/pkg.rs

@@ -388,7 +388,8 @@ impl BuildPlan {
                 }
 
                 let name = dep.package().unwrap_or(dep_name).to_string();
-                let source = dep_to_source(proj_path, dep)?;
+                let source =
+                    apply_patch(&name, &dep_to_source(proj_path, dep)?, manifest, proj_path)?;
                 let dep_pkg = Pkg { name, source };
                 Ok((dep_name, dep_pkg))
             })
@@ -882,10 +883,24 @@ pub fn graph_to_path_map(
                             bail!("missing path info for dependency: {}", &dep_name);
                         }
                     })?;
-                let rel_dep_path = detailed
-                    .path
-                    .as_ref()
-                    .ok_or_else(|| anyhow!("missing path info for dependency: {}", dep.name))?;
+                // Check if there is a patch for this dep
+                let patch = parent_manifest
+                    .patches()
+                    .find_map(|patches| patches.1.get(&dep_name));
+                // If there is one fetch the details.
+                let patch_details = patch.and_then(|patch| match patch {
+                    Dependency::Simple(_) => None,
+                    Dependency::Detailed(detailed) => Some(detailed),
+                });
+                // If there is a detail we should have the path.
+                // If not either we do not have a patch so we are checking dependencies of parent
+                // If we can't find the path there, either patch or dep is provided as a basic dependency, so we are missing the path info.
+                let rel_dep_path = if let Some(patch_details) = patch_details {
+                    patch_details.path.as_ref()
+                } else {
+                    detailed.path.as_ref()
+                }
+                .ok_or_else(|| anyhow!("missing path info for dep: {}", &dep_name))?;
                 let path = parent_path.join(rel_dep_path);
                 if !path.exists() {
                     bail!("pinned `path` dependency \"{}\" source missing", dep.name);
@@ -985,6 +1000,38 @@ pub(crate) fn fetch_deps(
     Ok((graph, path_map))
 }
 
+fn apply_patch(
+    name: &str,
+    source: &Source,
+    manifest: &Manifest,
+    parent_path: &Path,
+) -> Result<Source> {
+    match source {
+        // Check if the patch is for a git dependency.
+        Source::Git(git) => {
+            // Check if we got a patch for the git dependency.
+            if let Some(source_patches) = manifest
+                .patch
+                .as_ref()
+                .and_then(|patches| patches.get(git.repo.as_str()))
+            {
+                if let Some(patch) = source_patches.get(name) {
+                    Ok(dep_to_source(parent_path, patch)?)
+                } else {
+                    bail!(
+                        "Cannot find the patch for the {} for package {}",
+                        git.repo,
+                        name
+                    )
+                }
+            } else {
+                Ok(source.clone())
+            }
+        }
+        _ => Ok(source.clone()),
+    }
+}
+
 /// Produce a unique ID for a particular fetch pass.
 ///
 /// This is used in the temporary git directory and allows for avoiding contention over the git repo directory.
@@ -1013,7 +1060,12 @@ fn fetch_children(
     let parent_path = path_map[&parent_id].clone();
     for (dep_name, dep) in manifest.deps() {
         let name = dep.package().unwrap_or(dep_name).to_string();
-        let source = dep_to_source(&parent_path, dep)?;
+        let source = apply_patch(
+            &name,
+            &dep_to_source(&parent_path, dep)?,
+            manifest,
+            &parent_path,
+        )?;
         if offline_mode && !matches!(source, Source::Path(_)) {
             bail!("Unable to fetch pkg {:?} in offline mode", source);
         }
@@ -1292,7 +1344,9 @@ fn dep_to_source(pkg_path: &Path, dep: &Dependency) -> Result<Source> {
         Dependency::Detailed(ref det) => match (&det.path, &det.version, &det.git) {
             (Some(relative_path), _, _) => {
                 let path = pkg_path.join(relative_path);
-                Source::Path(path.canonicalize()?)
+                Source::Path(path.canonicalize().map_err(|err| {
+                    anyhow!("Cant apply patch from {}, cause: {}", relative_path, &err)
+                })?)
             }
             (_, _, Some(repo)) => {
                 let reference = match (&det.branch, &det.tag, &det.rev) {

test/src/e2e_vm_tests/test_programs/should_pass/forc/dependency_patching/Forc.lock

@@ -0,0 +1,14 @@
+[[package]]
+name = 'core'
+source = 'path+from-root-B0CAE5E4D7DDF437'
+dependencies = []
+
+[[package]]
+name = 'dependency_patching'
+source = 'root'
+dependencies = ['std']
+
+[[package]]
+name = 'std'
+source = 'path+from-root-B0CAE5E4D7DDF437'
+dependencies = ['core']

test/src/e2e_vm_tests/test_programs/should_pass/forc/dependency_patching/Forc.toml

@@ -0,0 +1,10 @@
+[project]
+authors = ["Fuel Labs <contact@fuel.sh>"]
+entry = "main.sw"
+license = "Apache-2.0"
+name = "dependency_patching"
+
+[dependencies]
+
+[patch.'https://github.com/fuellabs/sway']
+std = { path = "../../../../../../../sway-lib-std" }

test/src/e2e_vm_tests/test_programs/should_pass/forc/dependency_patching/json_abi_oracle.json

@@ -0,0 +1,14 @@
+[
+  {
+    "inputs": [],
+    "name": "main",
+    "outputs": [
+      {
+        "components": null,
+        "name": "",
+        "type": "u64"
+      }
+    ],
+    "type": "function"
+  }
+]

test/src/e2e_vm_tests/test_programs/should_pass/forc/dependency_patching/src/main.sw

@@ -0,0 +1,5 @@
+script;
+
+fn main() -> u64 {
+    0
+}

test/src/e2e_vm_tests/test_programs/should_pass/forc/dependency_patching/test.toml

@@ -0,0 +1 @@
+category = "compile"