Automatically inherit workspace fields when running cargo new

Signed-off-by: hi-rustin <rustin.liu@gmail.com>

Author: 0xPoe

src/cargo/ops/cargo_new.rs

@@ -1,5 +1,6 @@
 use crate::core::{Edition, Shell, Workspace};
 use crate::util::errors::CargoResult;
+use crate::util::toml::parse_document;
 use crate::util::{existing_vcs_repo, FossilRepo, GitRepo, HgRepo, PijulRepo};
 use crate::util::{restricted_names, Config};
 use anyhow::{anyhow, Context as _};
@@ -866,15 +867,115 @@ mod tests {
             }
         }
     }
-
-    if let Err(e) = Workspace::new(&path.join("Cargo.toml"), config) {
-        crate::display_warning_with_error(
-            "compiling this new package may not work due to invalid \
+    match Workspace::new(&path.join("Cargo.toml"), config) {
+        Ok(ws) => {
+            // Because we only inherit the package field of workspace for valid members of workspace,
+            // we did not inherit it directly above.
+            let root_manifest = paths::read(ws.root_manifest())?;
+            let workspace_document =
+                parse_document(root_manifest.as_str(), ws.root_manifest(), config)?;
+            if let Some(workspace_package_keys) = workspace_document
+                .get("workspace")
+                .and_then(|workspace| workspace.get("package"))
+                .and_then(|package| package.as_table())
+            {
+                // Because we need to keep the format of the `Cargo.toml` file,
+                // we can not use `toml_edit`/`toml` to modify the `Cargo.toml` file directly.
+                // Instead, we need to rewrite the `Cargo.toml` file with the inherited package fields.
+                return create_manifest_with_inherited_workspace_package_fields(
+                    opts,
+                    path,
+                    name,
+                    cargotoml_path_specifier.as_str(),
+                    workspace_package_keys,
+                );
+            }
+        }
+        Err(e) => {
+            crate::display_warning_with_error(
+                "compiling this new package may not work due to invalid \
              workspace configuration",
-            &e,
-            &mut config.shell(),
-        );
+                &e,
+                &mut config.shell(),
+            );
+        }
     }
 
     Ok(())
 }
+
+fn create_manifest_with_inherited_workspace_package_fields(
+    opts: &MkOptions<'_>,
+    path: &Path,
+    name: &str,
+    cargotoml_path_specifier: &str,
+    workspace_package_keys: &toml::value::Table,
+) -> CargoResult<()> {
+    if workspace_package_keys.is_empty() {
+        return Ok(());
+    }
+    // Try inherit the edition from the workspace if it is not specified.
+    let edition = match opts.edition {
+        Some(edition) => {
+            format!("edition = {}", toml::Value::String(edition.to_string()))
+        }
+        None => {
+            if workspace_package_keys.contains_key("edition") {
+                format!("edition.workspace = {}", toml::Value::Boolean(true))
+            } else {
+                format!(
+                    "edition = {}",
+                    toml::Value::String(Edition::LATEST_STABLE.to_string())
+                )
+            }
+        }
+    };
+    // Try inherit the version from the workspace if it is not specified.
+    let version = if workspace_package_keys.contains_key("version") {
+        format!("version.workspace = {}", toml::Value::Boolean(true))
+    } else {
+        "version = \"0.1.0\"".to_string()
+    };
+    // Try inherit the publish from the workspace if it is not specified.
+    let publish = match opts.registry {
+        Some(registry) => format!(
+            "publish = {}\n",
+            toml::Value::Array(vec!(toml::Value::String(registry.to_string())))
+        ),
+        None => {
+            if workspace_package_keys.contains_key("publish") {
+                format!("publish.workspace = {}\n", toml::Value::Boolean(true))
+            } else {
+                "".to_string()
+            }
+        }
+    };
+    // Inherit other keys from the workspace.
+    let workspace_package_fields = workspace_package_keys
+        .iter()
+        .filter(|(key, _)| *key != "edition" && *key != "version" && *key != "publish")
+        .map(|(key, _)| format!("{}.workspace = {}", key, toml::Value::Boolean(true)))
+        .collect::<Vec<String>>();
+    paths::write(
+        &path.join("Cargo.toml"),
+        format!(
+            r#"[package]
+name = "{}"
+{}
+{}
+{}{}
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+{}"#,
+            name,
+            version,
+            edition,
+            publish,
+            workspace_package_fields.join("\n"),
+            cargotoml_path_specifier
+        )
+        .as_bytes(),
+    )?;
+    return Ok(());
+}