Add new Client API

Signed-off-by: Helder Correia <174525+helderco@users.noreply.github.com>

tests/plan/client/commands/test.cue

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"strings"
+	"dagger.io/dagger"
+)
+
+dagger.#Plan & {
+	client: commands: {
+		normal: {
+			name: "echo"
+			args: ["hello europa"]
+		}
+		relative: {
+			name: "cat"
+			args: ["./test.txt"]
+		}
+		secret: {
+			name:   "tee"
+			stdout: dagger.#Secret
+			stdin:  "hello secretive europa"
+		}
+		error: {
+			name: "sh"
+			flags: "-c": ">&2 echo 'error'"
+			stderr: string
+		}
+		invalid: name: "foobar"
+	}
+	actions: {
+		image: dagger.#Pull & {
+			source: "alpine:3.15.0@sha256:e7d88de73db3d3fd9b2d63aa7f447a10fd0220b7cbf39803c803f2af9ba256b3"
+		}
+		test: {
+			invalid: dagger.#Exec & {
+				input: image.output
+				args: ["echo", client.commands.invalid.stdout]
+			}
+			valid: {
+				normal: dagger.#Exec & {
+					input: image.output
+					args: ["test", strings.TrimSpace(client.commands.normal.stdout), "=", "hello europa"]
+				}
+				relative: dagger.#Exec & {
+					input: image.output
+					args: ["test", strings.TrimSpace(client.commands.relative.stdout), "=", "test"]
+				}
+				error: dagger.#Exec & {
+					input: image.output
+					args: ["test", strings.TrimSpace(client.commands.error.stderr), "=", "error"]
+				}
+				secret: dagger.#Exec & {
+					input: image.output
+					mounts: secret: {
+						dest:     "/run/secrets/test"
+						contents: client.commands.secret.stdout
+					}
+					args: [
+						"sh", "-c",
+						#"""
+						test "$(cat /run/secrets/test)" = "hello secretive europa"
+						"""#,
+					]
+				}
+			}
+		}
+	}
+}

tests/plan/client/commands/test.txt

@@ -0,0 +1 @@
+test