fix(future): Emit `deno install` warning less often, suggest `deno install` in error message (#24706)

Two small changes:

- In our BYONM errors, suggest running `deno install` instead of `npm
install` if `DENO_FUTURE` is set
- Only emit warning about `deno install` changes if you do `deno install
<foo>` with deno_future unset

3 files changed, 17 insertions, 7 deletions

diff --git a/cli/npm/byonm.rs b/cli/npm/byonm.rs
index d10bb6b2a..86c9badac 100644
--- a/cli/npm/byonm.rs
+++ b/cli/npm/byonm.rs
@@ -286,9 +286,14 @@ impl CliNpmResolver for ByonmCliNpmResolver {
       concat!(
         "Could not find \"{}\" in a node_modules folder. ",
         "Deno expects the node_modules/ directory to be up to date. ",
-        "Did you forget to run `npm install`?"
+        "Did you forget to run `{}`?"
       ),
       alias,
+      if *crate::args::DENO_FUTURE {
+        "deno install"
+      } else {
+        "npm install"
+      }
     );
   }
 
diff --git a/cli/resolver.rs b/cli/resolver.rs
index c1bb8a0a5..c9940b406 100644
--- a/cli/resolver.rs
+++ b/cli/resolver.rs
@@ -233,8 +233,13 @@ impl CliNodeResolver {
           let package_json_path = package_folder.join("package.json");
           if !self.fs.exists_sync(&package_json_path) {
             return Err(anyhow!(
-              "Could not find '{}'. Deno expects the node_modules/ directory to be up to date. Did you forget to run `npm install`?",
-              package_json_path.display()
+              "Could not find '{}'. Deno expects the node_modules/ directory to be up to date. Did you forget to run `{}`?",
+              package_json_path.display(),
+              if *crate::args::DENO_FUTURE {
+                "deno install"
+              } else {
+                "npm install"
+              },
             ));
           }
         }
diff --git a/cli/tools/installer.rs b/cli/tools/installer.rs
index 01ed36711..d1beb79bb 100644
--- a/cli/tools/installer.rs
+++ b/cli/tools/installer.rs
@@ -283,12 +283,12 @@ pub async fn install_command(
   flags: Arc<Flags>,
   install_flags: InstallFlags,
 ) -> Result<(), AnyError> {
-  if !install_flags.global {
-    log::warn!("⚠️ `deno install` behavior will change in Deno 2. To preserve the current behavior use the `-g` or `--global` flag.");
-  }
-
   match install_flags.kind {
     InstallKind::Global(global_flags) => {
+      if !install_flags.global {
+        log::warn!("⚠️ `deno install` behavior will change in Deno 2. To preserve the current behavior use the `-g` or `--global` flag.");
+      }
+
       install_global(flags, global_flags).await
     }
     InstallKind::Local(maybe_add_flags) => {