fix(engine): no longer error if provided task is omitted by filter (#10051)

### Description

Fixes #9619

This PR makes it so we no longer error if the filter excludes a task
provided by the user. This is especially helpful when filters are not
static such as `--affected` or SCM based filters.

### Testing Instructions
Updated unit tests.

Before
```
# Task only defined on `@turbo/types`
[0 olszewski@macbookpro] /Users/olszewski/code/vercel/turborepo $ turbo copy-schema --filter=cli 
 WARNING  No locally installed `turbo` found. Using version: 2.4.4.
turbo 2.4.4

  × Missing tasks in project
  ╰─▶   × Could not find task `copy-schema` in project

# Task only defined at root

[1 olszewski@macbookpro] /Users/olszewski/code/vercel/turborepo $ turbo build check:toml --filter='!cli'
 WARNING  No locally installed `turbo` found. Using version: 2.4.4.
turbo 2.4.4

  × Missing tasks in project
  ╰─▶   × Could not find task `check:toml` in project
```

After
```
# Task only defined on `@turbo/types`
[0 olszewski@macbookpro] /Users/olszewski/code/vercel/turborepo $ turbo_dev copy-schema --filter=cli
 WARNING  No locally installed `turbo` found. Using version: 2.4.4.
turbo 2.4.4

• Packages in scope: cli
• Running copy-schema in 1 packages
• Remote caching enabled

No tasks were executed as part of this run.

 Tasks:    0 successful, 0 total
Cached:    0 cached, 0 total
  Time:    113ms 

# Task only defined at root
[0 olszewski@macbookpro] /Users/olszewski/code/vercel/turborepo $ turbo_dev check:toml --filter='!cli'
 WARNING  No locally installed `turbo` found. Using version: 2.4.4.
turbo 2.4.4

• Packages in scope: @turbo-internal/top-issues-gh-action, @turbo/benchmark, @turbo/codemod, @turbo/eslint-config, @turbo/exe-stub, @turbo/gen, @turbo/releaser, @turbo/telemetry, @turbo/test-utils, @turbo/tsconfig, @turbo/types, @turbo/utils, @turbo/workspaces, @turborepo-examples-tests/basic-npm, @turborepo-examples-tests/basic-pnpm, @turborepo-examples-tests/basic-yarn, @turborepo-examples-tests/kitchen-sink-npm, @turborepo-examples-tests/kitchen-sink-pnpm, @turborepo-examples-tests/kitchen-sink-yarn, @turborepo-examples-tests/non-monorepo-npm, @turborepo-examples-tests/non-monorepo-pnpm, @turborepo-examples-tests/non-monorepo-yarn, @turborepo-examples-tests/with-svelte-npm, @turborepo-examples-tests/with-svelte-pnpm, @turborepo-examples-tests/with-svelte-yarn, @turborepo-examples-tests/with-tailwind-npm, @turborepo-examples-tests/with-tailwind-pnpm, @turborepo-examples-tests/with-tailwind-yarn, cargo-sweep-action, create-turbo, eslint-config-turbo, eslint-plugin-turbo, prysk, turbo-ignore, turbo-vsc, turborepo-examples, turborepo-repository, turborepo-tests-helpers, turborepo-tests-integration
• Running check:toml in 39 packages
• Remote caching enabled

No tasks were executed as part of this run.

 Tasks:    0 successful, 0 total
Cached:    0 cached, 0 total
  Time:    123ms 


```

Author: chris-olszewski

crates/turborepo-lib/src/engine/builder.rs

@@ -259,7 +259,7 @@ impl<'a> EngineBuilder<'a> {
                 .task_id()
                 .unwrap_or_else(|| TaskId::new(workspace.as_ref(), task.task()));
 
-            if Self::has_task_definition(turbo_json_loader, workspace, task, &task_id)? {
+            if Self::has_task_definition_in_run(turbo_json_loader, workspace, task, &task_id)? {
                 missing_tasks.remove(task.as_inner());
 
                 // Even if a task definition was found, we _only_ want to add it as an entry
@@ -276,6 +276,33 @@ impl<'a> EngineBuilder<'a> {
             }
         }
 
+        {
+            // We can encounter IO errors trying to load turbo.jsons which prevents using
+            // `retain` in the standard way. Instead we store the possible error
+            // outside of the loop and short circuit checks if we've encountered an error.
+            let mut error = None;
+            missing_tasks.retain(|task_name, _| {
+                // If we've already encountered an error skip checking the rest.
+                if error.is_some() {
+                    return true;
+                }
+                match Self::has_task_definition_in_repo(
+                    turbo_json_loader,
+                    self.package_graph,
+                    task_name,
+                ) {
+                    Ok(has_defn) => !has_defn,
+                    Err(e) => {
+                        error.get_or_insert(e);
+                        true
+                    }
+                }
+            });
+            if let Some(err) = error {
+                return Err(err);
+            }
+        }
+
         if !missing_tasks.is_empty() {
             let missing_pkgs: HashMap<_, _> = missing_tasks
                 .iter()
@@ -463,8 +490,25 @@ impl<'a> EngineBuilder<'a> {
     }
 
     // Helper methods used when building the engine
+    /// Checks if there's a task definition somewhere in the repository
+    fn has_task_definition_in_repo(
+        loader: &TurboJsonLoader,
+        package_graph: &PackageGraph,
+        task_name: &TaskName<'static>,
+    ) -> Result<bool, Error> {
+        for (package, _) in package_graph.packages() {
+            let task_id = task_name
+                .task_id()
+                .unwrap_or_else(|| TaskId::new(package.as_str(), task_name.task()));
+            if Self::has_task_definition_in_run(loader, package, task_name, &task_id)? {
+                return Ok(true);
+            }
+        }
+        Ok(false)
+    }
 
-    fn has_task_definition(
+    /// Checks if there's a task definition in the current run
+    fn has_task_definition_in_run(
         loader: &TurboJsonLoader,
         workspace: &PackageName,
         task_name: &TaskName<'static>,
@@ -485,7 +529,12 @@ impl<'a> EngineBuilder<'a> {
 
         let Some(turbo_json) = turbo_json else {
             // If there was no turbo.json in the workspace, fallback to the root turbo.json
-            return Self::has_task_definition(loader, &PackageName::Root, task_name, task_id);
+            return Self::has_task_definition_in_run(
+                loader,
+                &PackageName::Root,
+                task_name,
+                task_id,
+            );
         };
 
         let task_id_as_name = task_id.as_task_name();
@@ -502,7 +551,7 @@ impl<'a> EngineBuilder<'a> {
         {
             Ok(true)
         } else if !matches!(workspace, PackageName::Root) {
-            Self::has_task_definition(loader, &PackageName::Root, task_name, task_id)
+            Self::has_task_definition_in_run(loader, &PackageName::Root, task_name, task_id)
         } else {
             Ok(false)
         }
@@ -788,7 +837,8 @@ mod test {
         let task_id = TaskId::try_from(task_id).unwrap();
 
         let has_def =
-            EngineBuilder::has_task_definition(&loader, &workspace, &task_name, &task_id).unwrap();
+            EngineBuilder::has_task_definition_in_run(&loader, &workspace, &task_name, &task_id)
+                .unwrap();
         assert_eq!(has_def, expected);
     }
 
@@ -1460,14 +1510,9 @@ mod test {
         let engine = EngineBuilder::new(&repo_root, &package_graph, &loader, false)
             .with_tasks(vec![Spanned::new(TaskName::from("app1#another"))])
             .with_workspaces(vec![PackageName::from("libA")])
-            .build();
-        assert!(engine.is_err());
-        let report = miette::Report::new(engine.unwrap_err());
-        let mut msg = String::new();
-        miette::JSONReportHandler::new()
-            .render_report(&mut msg, report.as_ref())
+            .build()
             .unwrap();
-        assert_json_snapshot!(msg);
+        assert_eq!(engine.tasks().collect::<Vec<_>>(), &[&TaskNode::Root]);
     }
 
     #[test]
@@ -1505,4 +1550,49 @@ mod test {
             .unwrap();
         assert_snapshot!(msg);
     }
+
+    #[test]
+    fn test_filter_removes_task_def() {
+        let repo_root_dir = TempDir::with_prefix("repo").unwrap();
+        let repo_root = AbsoluteSystemPathBuf::new(repo_root_dir.path().to_str().unwrap()).unwrap();
+        let package_graph = mock_package_graph(
+            &repo_root,
+            package_jsons! {
+                repo_root,
+                "app1" => ["libA"],
+                "libA" => []
+            },
+        );
+        let turbo_jsons = vec![
+            (
+                PackageName::Root,
+                turbo_json(json!({
+                    "tasks": {
+                        "build": { "dependsOn": ["^build"] },
+                    }
+                })),
+            ),
+            (
+                PackageName::from("app1"),
+                turbo_json(json!({
+                    "tasks": {
+                        "app1-only": {},
+                    }
+                })),
+            ),
+        ]
+        .into_iter()
+        .collect();
+        let loader = TurboJsonLoader::noop(turbo_jsons);
+        let engine = EngineBuilder::new(&repo_root, &package_graph, &loader, false)
+            .with_tasks(vec![Spanned::new(TaskName::from("app1-only"))])
+            .with_workspaces(vec![PackageName::from("libA")])
+            .build()
+            .unwrap();
+        assert_eq!(
+            engine.tasks().collect::<Vec<_>>(),
+            &[&TaskNode::Root],
+            "only the root task node should be present"
+        );
+    }
 }