From 15e410edae6532010544c944cdf5546a6b1ebbf1 Mon Sep 17 00:00:00 2001
From: Kristoffer Carlsson <kristoffer.carlsson@chalmers.se>
Date: Sun, 3 Jun 2018 17:37:36 +0200
Subject: [PATCH] fix preview of generate so it does not create any files
 (#330)

---
 stdlib/Pkg/src/REPLMode.jl |  2 +-
 stdlib/Pkg/src/generate.jl | 21 +++++++++++++--------
 stdlib/Pkg/test/pkg.jl     | 10 +++++++++-
 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/stdlib/Pkg/src/REPLMode.jl b/stdlib/Pkg/src/REPLMode.jl
index a44c7aa63e7a2..74540a5ee29e8 100644
--- a/stdlib/Pkg/src/REPLMode.jl
+++ b/stdlib/Pkg/src/REPLMode.jl
@@ -748,7 +748,7 @@ function do_generate!(ctx::Context, tokens::Vector{Token})
             cmderror("`generate` takes a name of the project to create")
         end
     end
-    API.generate(pkg)
+    API.generate(ctx, pkg)
 end
 
 function do_precompile!(ctx::Context, tokens::Vector{Token})
diff --git a/stdlib/Pkg/src/generate.jl b/stdlib/Pkg/src/generate.jl
index 6f2528c9899ae..bcaf8876f50c3 100644
--- a/stdlib/Pkg/src/generate.jl
+++ b/stdlib/Pkg/src/generate.jl
@@ -1,24 +1,29 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
-function generate(path::String)
+generate(path::String; kwargs...) = generate(Context(), path; kwargs...)
+function generate(ctx::Context, path::String; kwargs...)
+    Context!(ctx; kwargs...)
+    ctx.preview && preview_info()
     dir, pkg = dirname(path), basename(path)
     isdir(path) && cmderror("$(abspath(path)) already exists")
     printstyled("Generating"; color=:green, bold=true)
     print(" project $pkg:\n")
-    project(pkg, dir)
-    entrypoint(pkg, dir)
+    project(pkg, dir; preview=ctx.preview)
+    entrypoint(pkg, dir; preview=ctx.preview)
+    ctx.preview && preview_info()
     return
 end
 
-function genfile(f::Function, pkg::String, dir::String, file::String)
+function genfile(f::Function, pkg::String, dir::String, file::String; preview::Bool)
     path = joinpath(dir, pkg, file)
     println(stdout, "    $path")
+    preview && return
     mkpath(dirname(path))
     open(f, path, "w")
     return
 end
 
-function project(pkg::String, dir::String)
+function project(pkg::String, dir::String; preview::Bool)
     name = email = nothing
     gitname = LibGit2.getconfig("user.name", "")
     isempty(gitname) || (name = gitname)
@@ -46,7 +51,7 @@ function project(pkg::String, dir::String)
 
     authorstr = "[\"$name " * (email == nothing ? "" : "<$email>") * "\"]"
 
-    genfile(pkg, dir, "Project.toml") do io
+    genfile(pkg, dir, "Project.toml"; preview=preview) do io
         print(io,
             """
             authors = $authorstr
@@ -60,8 +65,8 @@ function project(pkg::String, dir::String)
     end
 end
 
-function entrypoint(pkg::String, dir)
-    genfile(pkg, dir, "src/$pkg.jl") do io
+function entrypoint(pkg::String, dir; preview::Bool)
+    genfile(pkg, dir, "src/$pkg.jl"; preview=preview) do io
         print(io,
            """
             module $pkg
diff --git a/stdlib/Pkg/test/pkg.jl b/stdlib/Pkg/test/pkg.jl
index f449dca197145..e3e427f9d5753 100644
--- a/stdlib/Pkg/test/pkg.jl
+++ b/stdlib/Pkg/test/pkg.jl
@@ -214,11 +214,19 @@ temp_pkg_dir() do project_path
     end
 end
 
-
 @testset "parse package url win" begin
     @test typeof(Pkg.REPLMode.parse_package("https://github.com/abc/ABC.jl"; context=Pkg.REPLMode.CMD_ADD)) == PackageSpec
 end
 
+@testset "preview generate" begin
+    mktempdir() do tmp
+        cd(tmp) do
+            Pkg.generate("Foo"; preview=true)
+            @test !isdir(joinpath(tmp, "Foo"))
+        end
+    end
+end
+
 include("repl.jl")
 
 end # module