feat(add/install): Flag to add dev dependency to package.json (#25495)

```
deno install --dev npm:chalk
```
Adds to `devDependencies` if a `package.json` is present, otherwise it
just adds to `imports` in `deno.json`

cli/args/flags.rs

@@ -85,6 +85,7 @@ impl FileFlags {
 #[derive(Clone, Debug, Default, Eq, PartialEq)]
 pub struct AddFlags {
   pub packages: Vec<String>,
+  pub dev: bool,
 }
 
 #[derive(Clone, Debug, Default, Eq, PartialEq)]
@@ -1585,6 +1586,15 @@ fn help_subcommand(app: &Command) -> Command {
     }))
 }
 
+fn add_dev_arg() -> Arg {
+  Arg::new("dev")
+    .long("dev")
+    .short('D')
+    .help("Add as a dev dependency")
+    .long_help("Add the package as a dev dependency. Note: This only applies when adding to a `package.json` file.")
+    .action(ArgAction::SetTrue)
+}
+
 fn add_subcommand() -> Command {
   command(
     "add",
@@ -1598,13 +1608,15 @@ You can add multiple dependencies at once:
     UnstableArgsConfig::None,
   )
   .defer(|cmd| {
-    cmd.arg(
+    cmd
+      .arg(
         Arg::new("packages")
           .help("List of packages to add")
           .required_unless_present("help")
           .num_args(1..)
           .action(ArgAction::Append),
       )
+      .arg(add_dev_arg())
   })
 }
 
@@ -2453,6 +2465,7 @@ These must be added to the path manually if required."), UnstableArgsConfig::Res
             .help("Install dependents of the specified entrypoint(s)"),
         )
         .arg(env_file_arg())
+        .arg(add_dev_arg().conflicts_with("entrypoint").conflicts_with("global"))
     })
 }
 
@@ -4091,7 +4104,8 @@ fn add_parse_inner(
   let packages = packages
     .unwrap_or_else(|| matches.remove_many::<String>("packages").unwrap())
     .collect();
-  AddFlags { packages }
+  let dev = matches.get_flag("dev");
+  AddFlags { packages, dev }
 }
 
 fn remove_parse(flags: &mut Flags, matches: &mut ArgMatches) {
@@ -10509,31 +10523,53 @@ mod tests {
   }
 
   #[test]
-  fn add_subcommand() {
+  fn add_or_install_subcommand() {
     let r = flags_from_vec(svec!["deno", "add"]);
     r.unwrap_err();
+    for cmd in ["add", "install"] {
+      let mk_flags = |flags: AddFlags| -> Flags {
+        match cmd {
+          "add" => Flags {
+            subcommand: DenoSubcommand::Add(flags),
+            ..Flags::default()
+          },
+          "install" => Flags {
+            subcommand: DenoSubcommand::Install(InstallFlags {
+              kind: InstallKind::Local(InstallFlagsLocal::Add(flags)),
+            }),
+            ..Flags::default()
+          },
+          _ => unreachable!(),
+        }
+      };
 
-    let r = flags_from_vec(svec!["deno", "add", "@david/which"]);
+      let r = flags_from_vec(svec!["deno", cmd, "@david/which"]);
       assert_eq!(
         r.unwrap(),
-      Flags {
-        subcommand: DenoSubcommand::Add(AddFlags {
+        mk_flags(AddFlags {
           packages: svec!["@david/which"],
-        }),
-        ..Flags::default()
-      }
+          dev: false,
+        }) // default is false
       );
 
-    let r = flags_from_vec(svec!["deno", "add", "@david/which", "@luca/hello"]);
+      let r = flags_from_vec(svec!["deno", cmd, "@david/which", "@luca/hello"]);
       assert_eq!(
         r.unwrap(),
-      Flags {
-        subcommand: DenoSubcommand::Add(AddFlags {
+        mk_flags(AddFlags {
           packages: svec!["@david/which", "@luca/hello"],
-        }),
-        ..Flags::default()
-      }
+          dev: false,
+        })
       );
+
+      let r = flags_from_vec(svec!["deno", cmd, "--dev", "npm:chalk"]);
+      assert_eq!(
+        r.unwrap(),
+        mk_flags(AddFlags {
+          packages: svec!["npm:chalk"],
+          dev: true,
+        }),
+      );
+    }
   }
 
   #[test]

cli/tools/registry/pm.rs

@@ -502,6 +502,7 @@ pub async fn add(
     }
   }
 
+  let dev = add_flags.dev;
   for selected_package in selected_packages {
     log::info!(
       "Add {}{}{}",
@@ -512,14 +513,14 @@ pub async fn add(
 
     if selected_package.package_name.starts_with("npm:") {
       if let Some(npm) = &mut npm_config {
-        npm.add(selected_package, false);
+        npm.add(selected_package, dev);
       } else {
-        deno_config.as_mut().unwrap().add(selected_package, false);
+        deno_config.as_mut().unwrap().add(selected_package, dev);
       }
     } else if let Some(deno) = &mut deno_config {
-      deno.add(selected_package, false);
+      deno.add(selected_package, dev);
     } else {
-      npm_config.as_mut().unwrap().add(selected_package, false);
+      npm_config.as_mut().unwrap().add(selected_package, dev);
     }
   }
 

tests/specs/add/dev/__test__.jsonc

@@ -0,0 +1,39 @@
+{
+  "tempDir": true,
+  "tests": {
+    "package_json": {
+      "steps": [
+        {
+          "args": "add --dev npm:@denotest/esm-basic",
+          "output": "add.out"
+        },
+        {
+          "args": [
+            "eval",
+            "console.log(Deno.readTextFileSync('package.json').trim())"
+          ],
+          "output": "package.json.out"
+        }
+      ]
+    },
+    "deno_json": {
+      "steps": [
+        {
+          "args": ["eval", "Deno.removeSync('package.json')"],
+          "output": ""
+        },
+        {
+          "args": "add --dev npm:@denotest/esm-basic",
+          "output": "add.out"
+        },
+        {
+          "args": [
+            "eval",
+            "console.log(Deno.readTextFileSync('deno.json').trim())"
+          ],
+          "output": "deno.json.out"
+        }
+      ]
+    }
+  }
+}

tests/specs/add/dev/add.out

@@ -0,0 +1,4 @@
+Add npm:@denotest/esm-basic@1.0.0
+Download http://localhost:4260/@denotest/esm-basic
+Download http://localhost:4260/@denotest/esm-basic/1.0.0.tgz
+Initialize @denotest/esm-basic@1.0.0

tests/specs/add/dev/deno.json

@@ -0,0 +1,3 @@
+{
+  "nodeModulesDir": "manual"
+}

tests/specs/add/dev/deno.json.out

@@ -0,0 +1,6 @@
+{
+  "nodeModulesDir": "manual",
+  "imports": {
+    "@denotest/esm-basic": "npm:@denotest/esm-basic@^1.0.0"
+  }
+}

tests/specs/add/dev/package.json

@@ -0,0 +1,3 @@
+{
+  "devDependencies": { "@denotest/esm-basic": "^1.0.0" }
+}

tests/specs/add/dev/package.json.out

@@ -0,0 +1,3 @@
+{
+  "devDependencies": { "@denotest/esm-basic": "^1.0.0" }
+}

tests/specs/install/install_add_dev/__test__.jsonc

@@ -0,0 +1,16 @@
+{
+  "tempDir": true,
+  "steps": [
+    {
+      "args": "install --dev npm:@denotest/esm-basic",
+      "output": "install.out"
+    },
+    {
+      "args": [
+        "eval",
+        "console.log(Deno.readTextFileSync('package.json').trim())"
+      ],
+      "output": "package.json.out"
+    }
+  ]
+}

tests/specs/install/install_add_dev/install.out

@@ -0,0 +1,4 @@
+Add npm:@denotest/esm-basic@1.0.0
+Download http://localhost:4260/@denotest/esm-basic
+Download http://localhost:4260/@denotest/esm-basic/1.0.0.tgz
+Initialize @denotest/esm-basic@1.0.0

tests/specs/install/install_add_dev/package.json

@@ -0,0 +1,3 @@
+{
+  "devDependencies": { "@denotest/esm-basic": "^1.0.0" }
+}

tests/specs/install/install_add_dev/package.json.out

@@ -0,0 +1,3 @@
+{
+  "devDependencies": { "@denotest/esm-basic": "^1.0.0" }
+}