Add a standalone shell installer

README.md

@@ -1,4 +1,4 @@
-<!-- Generated from private documentation source. Do not edit directly. Source SHA256: ec38d7acca3059eb364acc3b51a941e4df868b2f56436478d173874ad74cd4f9 -->
+<!-- Generated from private documentation source. Do not edit directly. Source SHA256: ba46d6ed5eb52d766e45733ec7480d618099cf0af61a3bb59904a5c4473386f8 -->
 
 # spritesmith
 
@@ -8,10 +8,10 @@ The client requires an API service and an account token. It does not contain a l
 
 ## Install
 
-With Go 1.27.2 or later:
+With Go 1.27.2 or later, install to `~/.local/bin` (add it to your PATH if necessary):
 
 ```sh
-go install github.com/aviorstudio/spritesmith/cmd/spritesmith@latest
+curl -fsSL https://spritesmith.ai/install | sh
 ```
 
 ## Configure

cmd/spritesmith/installer_test.go

@@ -0,0 +1,68 @@
+//go:build !windows
+
+package main
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+func TestCurlInstaller(t *testing.T) {
+	_, file, _, _ := runtime.Caller(0)
+	script := filepath.Join(filepath.Dir(file), "../../install.sh")
+	for _, fail := range []bool{false, true} {
+		name := "success"
+		if fail {
+			name = "failed build preserves existing executable"
+		}
+		t.Run(name, func(t *testing.T) {
+			root := t.TempDir()
+			bin, fake := filepath.Join(root, "bin"), filepath.Join(root, "commands")
+			for _, dir := range []string{bin, fake} {
+				if err := os.Mkdir(dir, 0700); err != nil {
+					t.Fatal(err)
+				}
+			}
+			if err := os.WriteFile(filepath.Join(bin, "spritesmith"), []byte("previous executable\n"), 0700); err != nil {
+				t.Fatal(err)
+			}
+			goCommand := `#!/bin/sh
+set -eu
+[ "$1" = install ]
+[ "$2" = 'github.com/aviorstudio/spritesmith/cmd/spritesmith@latest' ]
+printf 'new executable\n' > "$GOBIN/spritesmith"
+if [ "${INSTALL_BUILD_FAIL:-0}" = 1 ]; then exit 42; fi
+`
+			if err := os.WriteFile(filepath.Join(fake, "go"), []byte(goCommand), 0700); err != nil {
+				t.Fatal(err)
+			}
+			cmd := exec.Command("sh", script, "--install-dir", bin)
+			cmd.Env = append(os.Environ(), "PATH="+fake+string(os.PathListSeparator)+os.Getenv("PATH"))
+			if fail {
+				cmd.Env = append(cmd.Env, "INSTALL_BUILD_FAIL=1")
+			}
+			output, err := cmd.CombinedOutput()
+			if fail == (err == nil) {
+				t.Fatalf("unexpected result: %v\n%s", err, output)
+			}
+			body, err := os.ReadFile(filepath.Join(bin, "spritesmith"))
+			if err != nil {
+				t.Fatal(err)
+			}
+			want := "new executable\n"
+			if fail {
+				want = "previous executable\n"
+			}
+			if string(body) != want {
+				t.Fatalf("unexpected executable: %q", body)
+			}
+			if !fail && !strings.Contains(string(output), "Installed spritesmith") {
+				t.Fatalf("missing install receipt: %s", output)
+			}
+		})
+	}
+}

install.sh

@@ -0,0 +1,58 @@
+#!/bin/sh
+# Install spritesmith using the Go module's normal verification and build process.
+set -eu
+
+tool=spritesmith
+module=github.com/aviorstudio/spritesmith/cmd/spritesmith
+release=latest
+install_dir=${INSTALL_DIR:-"$HOME/.local/bin"}
+work_dir=
+stage_dir=
+fail() { printf '%s: %s\n' "$tool" "$*" >&2; exit 1; }
+cleanup() {
+    [ -z "$work_dir" ] || rm -rf "$work_dir"
+    [ -z "$stage_dir" ] || rm -rf "$stage_dir"
+}
+trap cleanup 0
+trap 'exit 129' HUP
+trap 'exit 130' INT
+trap 'exit 143' TERM
+while [ "$#" -gt 0 ]; do
+    case "$1" in
+        --version|-v|--install-dir)
+            [ "$#" -ge 2 ] || fail "$1 needs a value."
+            case "$1" in
+                --version|-v) release=$2 ;;
+                --install-dir) install_dir=$2 ;;
+            esac
+            shift 2 ;;
+        --help|-h)
+            printf 'Install %s with Go: [--version VERSION|latest] [--install-dir /absolute/path]\nDefaults: latest Go module, ~/.local/bin. Requires Go.\n' "$tool"
+            exit 0 ;;
+        *) fail "Unknown option: $1" ;;
+    esac
+done
+case "$install_dir" in /*) ;; *) fail 'The install directory must be an absolute path.' ;; esac
+command -v go >/dev/null 2>&1 || fail 'Install Go first, then run this command again.'
+case "$release" in
+    latest) ;;
+    v[0-9]*) ;;
+    [0-9]*) release=v$release ;;
+    *) fail 'Use latest or a Go module version such as v1.2.3.' ;;
+esac
+work_dir=$(mktemp -d "${TMPDIR:-/tmp}/$tool-install.XXXXXXXX") || fail 'Could not create a temporary directory.'
+mkdir "$work_dir/bin"
+printf 'Building %s from %s@%s...\n' "$tool" "$module" "$release"
+GOBIN="$work_dir/bin" go install "$module@$release" || fail 'Go installation failed; the installed binary was not changed.'
+[ -f "$work_dir/bin/$tool" ] && [ ! -L "$work_dir/bin/$tool" ] || fail 'Go did not produce a regular executable.'
+mkdir -p "$install_dir" || fail 'Choose a writable install directory.'
+[ ! -d "$install_dir/$tool" ] || fail 'The install destination is a directory.'
+stage_dir=$(mktemp -d "$install_dir/.$tool-install.XXXXXXXX") || fail 'Could not stage the executable.'
+cp "$work_dir/bin/$tool" "$stage_dir/$tool"
+chmod 755 "$stage_dir/$tool"
+mv -f "$stage_dir/$tool" "$install_dir/$tool"
+printf 'Installed %s at %s/%s\n' "$tool" "$install_dir" "$tool"
+case ":$PATH:" in
+    *":$install_dir:"*) ;;
+    *) printf 'Add %s to your PATH to run %s by name.\n' "$install_dir" "$tool" ;;
+esac