From 4b04e9feee75c7c7383217db811900a280ce0cde Mon Sep 17 00:00:00 2001
From: Meghan Denny <hello@nektro.net>
Date: Sat, 10 Jul 2021 16:12:20 -0700
Subject: [PATCH] move `detect_pkgname` and `detct_mainfile` from cmd/init to
 util

---
 src/cmd/init.zig   | 47 ++++++++++++++--------------------------------
 src/util/funcs.zig | 40 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 52 insertions(+), 35 deletions(-)

diff --git a/src/cmd/init.zig b/src/cmd/init.zig
index 55469cb52640a3243c7c0f9acf4d4c877e038e6d..be87f7787824ef74ba1f41c3dbeeafe23677f97e 100644
--- a/src/cmd/init.zig
+++ b/src/cmd/init.zig
@@ -7,8 +7,20 @@ const u = @import("./../util/index.zig");
 //
 
 pub fn execute(args: [][]u8) !void {
-    const name = try detect_pkgname(u.try_index([]const u8, args, 0, ""));
-    const mainf = try detct_mainfile(u.try_index([]const u8, args, 1, ""));
+    const name = u.detect_pkgname(u.try_index([]const u8, args, 0, ""), null) catch |err| switch (err) {
+        error.NoBuildZig => {
+            u.assert(false, "init requires a build.zig file", .{});
+            unreachable;
+        },
+        else => return err,
+    };
+    const mainf = u.detct_mainfile(u.try_index([]const u8, args, 1, ""), null, name) catch |err| switch (err) {
+        error.CantFindMain => {
+            u.assert(false, "unable to detect package entry point", .{});
+            unreachable;
+        },
+        else => return err,
+    };
 
     const file = try std.fs.cwd().createFile("zig.mod", .{});
     defer file.close();
@@ -21,34 +33,3 @@ pub fn execute(args: [][]u8) !void {
 
     u.print("Initialized a new package named {s} with entry point {s}", .{ name, mainf });
 }
-
-fn detect_pkgname(def: []const u8) ![]const u8 {
-    if (def.len > 0) {
-        return def;
-    }
-    u.assert(try u.does_file_exist("build.zig"), "init requires a build.zig file", .{});
-    const dpath = try std.fs.cwd().realpathAlloc(gpa, "build.zig");
-    const split = try u.split(dpath, std.fs.path.sep_str);
-    var name = split[split.len - 2];
-    name = u.trim_prefix(name, "zig-");
-    u.assert(name.len > 0, "package name must not be an empty string", .{});
-    return name;
-}
-
-fn detct_mainfile(def: []const u8) ![]const u8 {
-    if (def.len > 0) {
-        if (try u.does_file_exist(def)) {
-            if (std.mem.endsWith(u8, def, ".zig")) {
-                return def;
-            }
-        }
-    }
-    if (try u.does_file_exist(try std.fs.path.join(gpa, &.{ "src", "lib.zig" }))) {
-        return "src/lib.zig";
-    }
-    if (try u.does_file_exist(try std.fs.path.join(gpa, &.{ "src", "main.zig" }))) {
-        return "src/main.zig";
-    }
-    u.assert(false, "unable to detect package entry point", .{});
-    unreachable;
-}
diff --git a/src/util/funcs.zig b/src/util/funcs.zig
index fe814321c639ac5a43da637c785adc4a014071f4..c29f64ed773b75effd8e836ec208dbf8c1298bdc 100644
--- a/src/util/funcs.zig
+++ b/src/util/funcs.zig
@@ -49,8 +49,8 @@ pub fn trim_prefix(in: []const u8, prefix: []const u8) []const u8 {
     return in;
 }
 
-pub fn does_file_exist(fpath: []const u8) !bool {
-    const file = std.fs.cwd().openFile(fpath, .{}) catch |e| switch (e) {
+pub fn does_file_exist(fpath: []const u8, dir: ?std.fs.Dir) !bool {
+    const file = (dir orelse std.fs.cwd()).openFile(fpath, .{}) catch |e| switch (e) {
         error.FileNotFound => return false,
         error.IsDir => return true,
         else => return e,
@@ -265,3 +265,39 @@ pub fn slice(comptime T: type, input: []const T, from: usize, to: usize) []const
     const t = std.math.min(to, input.len);
     return input[f..t];
 }
+
+pub fn detect_pkgname(override: []const u8, dir: ?std.fs.Dir) ![]const u8 {
+    if (override.len > 0) {
+        return override;
+    }
+    if (!(try does_file_exist("build.zig", dir))) {
+        return error.NoBuildZig;
+    }
+    const dpath = try (dir orelse std.fs.cwd()).realpathAlloc(gpa, "build.zig");
+    const splitP = try split(dpath, std.fs.path.sep_str);
+    var name = splitP[splitP.len - 2];
+    name = trim_prefix(name, "zig-");
+    assert(name.len > 0, "package name must not be an empty string", .{});
+    return name;
+}
+
+pub fn detct_mainfile(override: []const u8, dir: ?std.fs.Dir, name: []const u8) ![]const u8 {
+    if (override.len > 0) {
+        if (try does_file_exist(override, dir)) {
+            if (std.mem.endsWith(u8, override, ".zig")) {
+                return override;
+            }
+        }
+    }
+    const namedotzig = try std.mem.concat(gpa, u8, &.{ name, ".zig" });
+    if (try does_file_exist(namedotzig, dir)) {
+        return namedotzig;
+    }
+    if (try does_file_exist(try std.fs.path.join(gpa, &.{ "src", "lib.zig" }), dir)) {
+        return "src/lib.zig";
+    }
+    if (try does_file_exist(try std.fs.path.join(gpa, &.{ "src", "main.zig" }), dir)) {
+        return "src/main.zig";
+    }
+    return error.CantFindMain;
+}
-- 
2.54.0