Cargo test quicker by not building untested examples when filtered

src/bin/cargo/commands/fix.rs

@@ -1,6 +1,6 @@
 use crate::command_prelude::*;
 
-use cargo::ops::{self, CompileFilter, FilterRule};
+use cargo::ops::{self, CompileFilter, FilterRule, LibRule};
 
 pub fn cli() -> App {
     subcommand("fix")
@@ -127,7 +127,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
     if let CompileFilter::Default { .. } = opts.filter {
         opts.filter = CompileFilter::Only {
             all_targets: true,
-            lib: true,
+            lib: LibRule::Default,
             bins: FilterRule::All,
             examples: FilterRule::All,
             benches: FilterRule::All,

src/bin/cargo/commands/run.rs

@@ -49,7 +49,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
             .filter_map(|pkg| pkg.manifest().default_run())
             .collect();
         if default_runs.len() == 1 {
-            compile_opts.filter = CompileFilter::new(
+            compile_opts.filter = CompileFilter::from_raw_arguments(
                 false,
                 vec![default_runs[0].to_owned()],
                 false,

src/bin/cargo/commands/test.rs

@@ -1,4 +1,4 @@
-use cargo::ops::{self, CompileFilter};
+use cargo::ops::{self, CompileFilter, FilterRule, LibRule};
 
 use crate::command_prelude::*;
 
@@ -94,6 +94,17 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
 
     let mut compile_opts = args.compile_options(config, CompileMode::Test, Some(&ws))?;
 
+    // `TESTNAME` is actually an argument of the test binary, but it's
+    // important, so we explicitly mention it and reconfigure.
+    let test_name: Option<&str> = args.value_of("TESTNAME");
+    let mut test_args = vec![];
+    test_args.extend(test_name.into_iter().map(|s| s.to_string()));
+    test_args.extend(
+        args.values_of("args")
+            .unwrap_or_default()
+            .map(|s| s.to_string()),
+    );
+
     let no_run = args.is_present("no-run");
     let doc = args.is_present("doc");
     if doc {
@@ -111,17 +122,22 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
         }
         compile_opts.build_config.mode = CompileMode::Doctest;
         compile_opts.filter = ops::CompileFilter::new(
-            true,
-            Vec::new(),
-            false,
-            Vec::new(),
-            false,
-            Vec::new(),
-            false,
-            Vec::new(),
-            false,
-            false,
+            LibRule::True,
+            FilterRule::none(),
+            FilterRule::none(),
+            FilterRule::none(),
+            FilterRule::none(),
         );
+    } else if test_name.is_some() {
+        if let CompileFilter::Default { .. } = compile_opts.filter {
+            compile_opts.filter = ops::CompileFilter::new(
+                LibRule::Default, // compile the library, so the unit tests can be run filtered
+                FilterRule::All,    // compile the binaries, so the unit tests in binaries can be run filtered
+                FilterRule::All,    // compile the tests, so the integration tests can be run filtered
+                FilterRule::none(), // specify --examples to unit test binaries filtered
+                FilterRule::none(), // specify --benches to unit test benchmarks filtered
+            ); // also, specify --doc to run doc tests filtered
+        }
     }
 
     let ops = ops::TestOptions {
@@ -130,16 +146,6 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
         compile_opts,
     };
 
-    // `TESTNAME` is actually an argument of the test binary, but it's
-    // important, so we explicitly mention it and reconfigure.
-    let mut test_args = vec![];
-    test_args.extend(args.value_of("TESTNAME").into_iter().map(|s| s.to_string()));
-    test_args.extend(
-        args.values_of("args")
-            .unwrap_or_default()
-            .map(|s| s.to_string()),
-    );
-
     let err = ops::run_tests(&ws, &ops, &test_args)?;
     match err {
         None => Ok(()),

src/cargo/ops/cargo_compile.rs

@@ -172,6 +172,16 @@ impl Packages {
     }
 }
 
+#[derive(Debug, PartialEq, Eq)]
+pub enum LibRule {
+    /// Include the library, fail if not present
+    True,
+    /// Include the library if present
+    Default,
+    /// Exclude the library
+    False,
+}
+
 #[derive(Debug)]
 pub enum FilterRule {
     All,
@@ -186,7 +196,7 @@ pub enum CompileFilter {
     },
     Only {
         all_targets: bool,
-        lib: bool,
+        lib: LibRule,
         bins: FilterRule,
         examples: FilterRule,
         tests: FilterRule,
@@ -349,6 +359,10 @@ impl FilterRule {
         }
     }
 
+    pub fn none() -> FilterRule {
+        FilterRule::Just(Vec::new())
+    }
+
     fn matches(&self, target: &Target) -> bool {
         match *self {
             FilterRule::All => true,
@@ -372,7 +386,8 @@ impl FilterRule {
 }
 
 impl CompileFilter {
-    pub fn new(
+    /// Construct a CompileFilter from raw command line arguments.
+    pub fn from_raw_arguments(
         lib_only: bool,
         bins: Vec<String>,
         all_bins: bool,
@@ -384,6 +399,7 @@ impl CompileFilter {
         all_bens: bool,
         all_targets: bool,
     ) -> CompileFilter {
+        let rule_lib = if lib_only { LibRule::True } else { LibRule::False };
         let rule_bins = FilterRule::new(bins, all_bins);
         let rule_tsts = FilterRule::new(tsts, all_tsts);
         let rule_exms = FilterRule::new(exms, all_exms);
@@ -392,21 +408,34 @@ impl CompileFilter {
         if all_targets {
             CompileFilter::Only {
                 all_targets: true,
-                lib: true,
+                lib: LibRule::Default,
                 bins: FilterRule::All,
                 examples: FilterRule::All,
                 benches: FilterRule::All,
                 tests: FilterRule::All,
             }
-        } else if lib_only
+        } else {
+            CompileFilter::new(rule_lib, rule_bins, rule_tsts, rule_exms, rule_bens)
+        }
+    }
+
+    /// Construct a CompileFilter from underlying primitives.
+    pub fn new(
+        rule_lib: LibRule,
+        rule_bins: FilterRule,
+        rule_tsts: FilterRule,
+        rule_exms: FilterRule,
+        rule_bens: FilterRule,
+    ) -> CompileFilter {
+        if rule_lib == LibRule::True
             || rule_bins.is_specific()
             || rule_tsts.is_specific()
             || rule_exms.is_specific()
             || rule_bens.is_specific()
         {
             CompileFilter::Only {
                 all_targets: false,
-                lib: lib_only,
+                lib: rule_lib,
                 bins: rule_bins,
                 examples: rule_exms,
                 benches: rule_bens,
@@ -442,7 +471,7 @@ impl CompileFilter {
         match *self {
             CompileFilter::Default { .. } => true,
             CompileFilter::Only {
-                lib,
+                ref lib,
                 ref bins,
                 ref examples,
                 ref tests,
@@ -454,7 +483,11 @@ impl CompileFilter {
                     TargetKind::Test => tests,
                     TargetKind::Bench => benches,
                     TargetKind::ExampleBin | TargetKind::ExampleLib(..) => examples,
-                    TargetKind::Lib(..) => return lib,
+                    TargetKind::Lib(..) => return match *lib {
+                        LibRule::True => true,
+                        LibRule::Default => true,
+                        LibRule::False => false,
+                    },
                     TargetKind::CustomBuild => return false,
                 };
                 rule.matches(target)
@@ -608,13 +641,13 @@ fn generate_targets<'a>(
         }
         CompileFilter::Only {
             all_targets,
-            lib,
+            ref lib,
             ref bins,
             ref examples,
             ref tests,
             ref benches,
         } => {
-            if lib {
+            if *lib != LibRule::False {
                 let mut libs = Vec::new();
                 for proposal in filter_targets(packages, Target::is_lib, false, build_config.mode) {
                     let Proposal { target, pkg, .. } = proposal;
@@ -628,7 +661,7 @@ fn generate_targets<'a>(
                         libs.push(proposal)
                     }
                 }
-                if !all_targets && libs.is_empty() {
+                if !all_targets && libs.is_empty() && *lib == LibRule::True {
                     let names = packages.iter().map(|pkg| pkg.name()).collect::<Vec<_>>();
                     if names.len() == 1 {
                         failure::bail!("no library targets found in package `{}`", names[0]);

src/cargo/ops/mod.rs

@@ -1,6 +1,6 @@
 pub use self::cargo_clean::{clean, CleanOptions};
 pub use self::cargo_compile::{compile, compile_with_exec, compile_ws, CompileOptions};
-pub use self::cargo_compile::{CompileFilter, FilterRule, Packages};
+pub use self::cargo_compile::{CompileFilter, FilterRule, LibRule, Packages};
 pub use self::cargo_doc::{doc, DocOptions};
 pub use self::cargo_fetch::{fetch, FetchOptions};
 pub use self::cargo_generate_lockfile::generate_lockfile;

src/cargo/util/command_prelude.rs

@@ -328,7 +328,7 @@ pub trait ArgMatchesExt {
             all_features: self._is_present("all-features"),
             no_default_features: self._is_present("no-default-features"),
             spec,
-            filter: CompileFilter::new(
+            filter: CompileFilter::from_raw_arguments(
                 self._is_present("lib"),
                 self._values_of("bin"),
                 self._is_present("bins"),

tests/testsuite/build.rs

@@ -1955,7 +1955,7 @@ fn explicit_examples() {
         )
         .build();
 
-    p.cargo("test -v").run();
+    p.cargo("build --examples").run();
     p.process(&p.bin("examples/hello"))
         .with_stdout("Hello, World!\n")
         .run();
@@ -2126,7 +2126,7 @@ fn implicit_examples() {
         )
         .build();
 
-    p.cargo("test").run();
+    p.cargo("build --examples").run();
     p.process(&p.bin("examples/hello"))
         .with_stdout("Hello, World!\n")
         .run();
@@ -2739,13 +2739,13 @@ fn example_bin_same_name() {
         .file("examples/foo.rs", "fn main() {}")
         .build();
 
-    p.cargo("test --no-run -v").run();
+    p.cargo("build --examples").run();
 
     assert!(!p.bin("foo").is_file());
     // We expect a file of the form bin/foo-{metadata_hash}
     assert!(p.bin("examples/foo").is_file());
 
-    p.cargo("test --no-run -v").run();
+    p.cargo("build --examples").run();
 
     assert!(!p.bin("foo").is_file());
     // We expect a file of the form bin/foo-{metadata_hash}
@@ -4212,7 +4212,7 @@ fn inferred_examples() {
         .file("examples/baz/main.rs", "fn main() {}")
         .build();
 
-    p.cargo("test").run();
+    p.cargo("build --examples").run();
     assert!(p.bin("examples/bar").is_file());
     assert!(p.bin("examples/baz").is_file());
 }

tests/testsuite/freshness.rs

@@ -247,7 +247,6 @@ fn changing_profiles_caches_targets() {
             "\
 [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
 [RUNNING] target[..]debug[..]deps[..]foo-[..][EXE]
-[DOCTEST] foo
 ",
         )
         .run();

tests/testsuite/test.rs

@@ -163,7 +163,8 @@ fn cargo_test_verbose() {
 [COMPILING] foo v0.5.0 ([CWD])
 [RUNNING] `rustc [..] src/main.rs [..]`
 [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
-[RUNNING] `[..]target/debug/deps/foo-[..][EXE] hello`",
+[RUNNING] `[CWD]/target/debug/deps/foo-[..] hello`
+",
         )
         .with_stdout_contains("test test_hello ... ok")
         .run();
@@ -601,21 +602,21 @@ fn pass_through_command_line() {
 [COMPILING] foo v0.0.1 ([CWD])
 [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
 [RUNNING] target/debug/deps/foo-[..][EXE]
-[DOCTEST] foo",
+",
         )
+        .with_stdout_contains("running 1 test")
         .with_stdout_contains("test bar ... ok")
-        .with_stdout_contains("running 0 tests")
         .run();
 
     p.cargo("test foo")
         .with_stderr(
             "\
 [FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
 [RUNNING] target/debug/deps/foo-[..][EXE]
-[DOCTEST] foo",
+",
         )
+        .with_stdout_contains("running 1 test")
         .with_stdout_contains("test foo ... ok")
-        .with_stdout_contains("running 0 tests")
         .run();
 }
 
@@ -1462,6 +1463,37 @@ fn test_run_implicit_example_target() {
         .run();
 }
 
+#[test]
+fn test_filtered_excludes_compiling_examples() {
+    let p = project()
+        .file(
+            "src/lib.rs",
+            "#[cfg(test)] mod tests { #[test] fn foo() { assert!(true); } }",
+        )
+        .file("examples/ex1.rs", "fn main() {}")
+        .build();
+
+    p.cargo("test -v foo")
+        .with_stdout(
+            "
+running 1 test
+test tests::foo ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
+
+",
+        )
+        .with_stderr("\
+[COMPILING] foo v0.0.1 ([CWD])
+[RUNNING] `rustc --crate-name foo src/lib.rs [..] --test [..]`
+[FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
+[RUNNING] `[CWD]/target/debug/deps/foo-[..] foo`
+",
+        )
+        .with_stderr_does_not_contain("[RUNNING][..]rustc[..]ex1[..]")
+        .run();
+}
+
 #[test]
 fn test_no_harness() {
     let p = project()