Auto merge of #7827 - Kinrany:7656-format-placeholder-code-when-generating-a-crate, r=ehuss

Format placeholder code when generating a crate

When generating source files in `cargo new` and `cargo init`, try to run `rustfmt` CLI on them.

If it fails, log the error and proceed.

Tests:
* Works for `cargo init --lib`
* No changes in behavior if `rustfmt` is missing

Closes #7656

Author: bors

ci/azure-test-all.yml

@@ -16,6 +16,10 @@ steps:
 - bash: rustup component add clippy || echo "clippy not available"
   displayName: "Install clippy (maybe)"
 
+# Some tests also rely on rustfmt
+- bash: rustup component add rustfmt || echo "rustfmt not available"
+  displayName: "Install rustfmt (maybe)"
+
 # Deny warnings on CI to avoid warnings getting into the codebase, and note the
 # `force-system-lib-on-osx` which is intended to fix compile issues on OSX where
 # compiling curl from source on OSX yields linker errors on Azure.

crates/cargo-test-support/src/lib.rs

@@ -1801,9 +1801,9 @@ pub fn slow_cpu_multiplier(main: u64) -> Duration {
     Duration::from_secs(*SLOW_CPU_MULTIPLIER * main)
 }
 
-pub fn clippy_is_available() -> bool {
-    if let Err(e) = process("clippy-driver").arg("-V").exec_with_output() {
-        eprintln!("clippy-driver not available, skipping clippy test");
+pub fn command_is_available(cmd: &str) -> bool {
+    if let Err(e) = process(cmd).arg("-V").exec_with_output() {
+        eprintln!("{} not available, skipping tests", cmd);
         eprintln!("{:?}", e);
         false
     } else {

src/cargo/ops/cargo_new.rs

@@ -12,7 +12,8 @@ use std::fmt;
 use std::fs;
 use std::io::{BufRead, BufReader, ErrorKind};
 use std::path::{Path, PathBuf};
-use std::str::FromStr;
+use std::process::Command;
+use std::str::{from_utf8, FromStr};
 
 use toml;
 
@@ -707,6 +708,16 @@ mod tests {
             .unwrap_or(false)
         {
             paths::write(&path_of_source_file, default_file_content)?;
+
+            // Format the newly created source file
+            match Command::new("rustfmt").arg(&path_of_source_file).output() {
+                Err(e) => log::warn!("failed to call rustfmt: {}", e),
+                Ok(output) => {
+                    if !output.status.success() {
+                        log::warn!("rustfmt failed: {:?}", from_utf8(&output.stdout));
+                    }
+                }
+            };
         }
     }
 

tests/testsuite/cache_messages.rs

@@ -1,7 +1,7 @@
 //! Tests for caching compiler diagnostics.
 
 use cargo_test_support::{
-    basic_manifest, clippy_is_available, is_coarse_mtime, process, project, registry::Package,
+    basic_manifest, command_is_available, is_coarse_mtime, process, project, registry::Package,
     sleep_ms,
 };
 use std::path::Path;
@@ -276,7 +276,7 @@ fn fix() {
 
 #[cargo_test]
 fn clippy() {
-    if !clippy_is_available() {
+    if !command_is_available("clippy-driver") {
         return;
     }
 

tests/testsuite/clippy.rs

@@ -1,11 +1,11 @@
 //! Tests for the `cargo clippy` command.
 
-use cargo_test_support::{clippy_is_available, project, registry::Package};
+use cargo_test_support::{command_is_available, project, registry::Package};
 
 #[cargo_test]
 // Clippy should never be considered fresh.
 fn clippy_force_rebuild() {
-    if !clippy_is_available() {
+    if !command_is_available("clippy-driver") {
         return;
     }
 
@@ -43,7 +43,7 @@ fn clippy_force_rebuild() {
 
 #[cargo_test]
 fn clippy_passes_args() {
-    if !clippy_is_available() {
+    if !command_is_available("clippy-driver") {
         return;
     }
 

tests/testsuite/fix.rs

@@ -3,7 +3,7 @@
 use std::fs::File;
 
 use cargo_test_support::git;
-use cargo_test_support::{basic_manifest, clippy_is_available, project};
+use cargo_test_support::{basic_manifest, command_is_available, project};
 
 use std::io::Write;
 
@@ -1253,7 +1253,7 @@ fn fix_in_existing_repo_weird_ignore() {
 
 #[cargo_test]
 fn fix_with_clippy() {
-    if !clippy_is_available() {
+    if !command_is_available("clippy-driver") {
         return;
     }
 

tests/testsuite/init.rs

@@ -6,7 +6,7 @@ use std::fs::{self, File};
 use std::io::prelude::*;
 use std::process::Command;
 
-use cargo_test_support::{paths, Execs};
+use cargo_test_support::{command_is_available, paths, Execs};
 
 fn cargo_process(s: &str) -> Execs {
     let mut execs = cargo_test_support::cargo_process(s);
@@ -657,3 +657,50 @@ fn no_filename() {
         )
         .run();
 }
+
+#[cargo_test]
+fn formats_source() {
+    if !command_is_available("rustfmt") {
+        return;
+    }
+
+    fs::write(&paths::root().join("rustfmt.toml"), "tab_spaces = 2").unwrap();
+
+    cargo_process("init --lib")
+        .env("USER", "foo")
+        .with_stderr("[CREATED] library package")
+        .run();
+
+    assert_eq!(
+        fs::read_to_string(paths::root().join("src/lib.rs")).unwrap(),
+        r#"#[cfg(test)]
+mod tests {
+  #[test]
+  fn it_works() {
+    assert_eq!(2 + 2, 4);
+  }
+}
+"#
+    );
+}
+
+#[cargo_test]
+fn ignores_failure_to_format_source() {
+    cargo_process("init --lib")
+        .env("USER", "foo")
+        .env("PATH", "") // pretend that `rustfmt` is missing
+        .with_stderr("[CREATED] library package")
+        .run();
+
+    assert_eq!(
+        fs::read_to_string(paths::root().join("src/lib.rs")).unwrap(),
+        r#"#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        assert_eq!(2 + 2, 4);
+    }
+}
+"#
+    );
+}