sdk/fidl/fuchsia.component.test/realm_builder.fidl

// Copyright 2021 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
@available(added=7)
library fuchsia.component.test;

using fuchsia.component;
using fuchsia.component.config;
using fuchsia.component.decl;
using fuchsia.component.runner;
using fuchsia.component.types;
using fuchsia.data;
using fuchsia.mem;
using fuchsia.io;
using fuchsia.url;

// The Realm Builder Server will include a local component's name in its
// program dictionary under this string. Clients should use this value when
// extracting a local component's name.
const LOCAL_COMPONENT_NAME_KEY string = "LOCAL_COMPONENT_NAME";

/// This protocol can be used to instruct the Realm Builder Server to begin
/// creating a new realm.
@discoverable
closed protocol RealmBuilderFactory {
    /// Creates a new RealmBuilder. The client end of `realm_server_end` can be
    /// used to mutate the realm that is being constructed, by doing things such
    /// as adding new children to the realm or adding capability routes between
    /// them. The client end of `builder_server_end` is used to finalize the
    /// realm, after which point it can be launched in a collection.
    ///
    /// `pkg_dir_handle` is a handle to the test package. The realm builder
    /// client typically passes a handle to its own `/pkg` directory, and
    /// bundles the `other-component` into the same package.
    strict Create(resource struct {
        pkg_dir_handle client_end:fuchsia.io.Directory;
        realm_server_end server_end:Realm;
        builder_server_end server_end:Builder;
    }) -> () error RealmBuilderError;

    /// Identical to `Create`, but instead of the realm being empty by default
    /// it contains the contents of the manifest located in the test package at
    /// the path indicated by `relative_url`, which must be a fragment-only URL
    /// (for example, `#meta/other-component.cm`; see
    /// https://fuchsia.dev/fuchsia-src/reference/components/url#relative-fragment-only).
    strict CreateFromRelativeUrl(resource struct {
        pkg_dir_handle client_end:fuchsia.io.Directory;
        relative_url fuchsia.url.Url;
        realm_server_end server_end:Realm;
        builder_server_end server_end:Builder;
    }) -> () error RealmBuilderError;
};

/// Errors that may be returned by the `Realm` and `Builder` protocols.
///
/// Will be renamed to `RealmBuilderError` once the other definition under this
/// name earlier in this file is removed.
type RealmBuilderError = strict enum : uint32 {
    /// Child cannot be added to the realm, as there is already a child in the
    /// realm with that name.
    CHILD_ALREADY_EXISTS = 0;

    /// A legacy component URL was given to `AddChild`, or a modern component
    /// url was given to `AddLegacyChild`.
    INVALID_MANIFEST_EXTENSION = 1;

    /// A component declaration failed validation.
    INVALID_COMPONENT_DECL = 2;

    /// The referenced child does not exist.
    NO_SUCH_CHILD = 3;

    /// The component declaration for the referenced child cannot be viewed nor
    /// manipulated by RealmBuilder, because the child was added to the realm
    /// using an URL that was neither a fragment-only nor a legacy URL.
    CHILD_DECL_NOT_VISIBLE = 4;

    /// The source does not exist.
    NO_SUCH_SOURCE = 5;

    /// A target does not exist.
    NO_SUCH_TARGET = 6;

    /// The `capabilities` field is empty.
    CAPABILITIES_EMPTY = 7;

    /// The `targets` field is empty.
    TARGETS_EMPTY = 8;

    /// The `from` value is equal to one of the elements in `to`.
    SOURCE_AND_TARGET_MATCH = 9;

    /// The test package does not contain the component declaration referenced
    /// by a fragment-only component URL.
    DECL_NOT_FOUND = 10;

    /// Encountered an I/O error when attempting to read a component declaration
    /// referenced by a fragment-only component URL from the test package.
    DECL_READ_ERROR = 11;

    /// The `Build` function has been called multiple times on this channel.
    BUILD_ALREADY_CALLED = 12;

    /// A capability is invalid. This may occur if a required field is empty or
    /// if an unsupported type is received.
    CAPABILITY_INVALID = 13;

    /// The handle the client provided for the child realm is not usable.
    INVALID_CHILD_REALM_HANDLE = 14;

    /// `ReplaceComponentDecl` was called on a legacy or local component with a
    /// program declaration that did not match the one from the old component
    /// declaration. This could render a legacy or local component
    /// non-functional, and is disallowed.
    IMMUTABLE_PROGRAM = 15;

    /// The URL provided to `RealmBuilderFactory.CreateFromRelativeURL` is not a
    /// fragment-only component URL.
    URL_IS_NOT_RELATIVE = 16;

    /// The handle the client provided for the test's pkg directory is not
    /// usable.
    INVALID_PKG_DIR_HANDLE = 17;

    /// The component does not have a config schema defined. Attempting to
    /// set a config value is not allowed.
    NO_CONFIG_SCHEMA = 18;

    /// The component's config schema does not have a field with that name.
    NO_SUCH_CONFIG_FIELD = 19;

    /// A config value is invalid. This may mean a type mismatch or an issue
    /// with constraints like string/vector length.
    CONFIG_VALUE_INVALID = 20;

    /// A config value cannot be set because the realm has not chosen its override
    /// policy.
    @available(added=9)
    CONFIG_OVERRIDE_UNSUPPORTED = 21;
};

closed protocol Builder {
    /// Assembles the realm being constructed and returns the URL for the root
    /// component in the realm, which may then be used to create a new component
    /// in any collection where fuchsia-test-component is properly set up. Once
    /// this is called, any Realm channels for the realm will no longer be
    /// usable. The `runner` argument must be provided if the `AddLocalChild`
    /// function has been used in this realm, as this runner channel will be
    /// used to inform the client when to start and stop running any local
    /// component implementations.
    ///
    /// Errors:
    /// - `INVALID_COMPONENT_DECL`: A component declaration failed validaiton.
    /// - `BUILD_ALREADY_CALLED`: The `Build` function has been called multiple
    ///   times on this channel.
    strict Build(resource struct {
        runner client_end:fuchsia.component.runner.ComponentRunner;
    }) -> (struct {
        root_component_url string:fuchsia.component.types.MAX_URL_LENGTH;
    }) error RealmBuilderError;
};

/// A capability that can be routed around a realm using `AddRoute`.
///
/// Will be renamed to `Capability` once the other definition under this name
/// earlier in this file is removed.
type Capability = flexible union {
    1: protocol Protocol;
    2: directory Directory;
    3: storage Storage;
    4: service Service;
    @available(removed=11)
    5: event Event;
    @available(added=9)
    6: event_stream EventStream;
    @available(added=HEAD)
    7: config Config;
};

/// A protocol capability
type Protocol = table {
    /// The name of the capability. This is usually the name of the FIDL
    /// protocol, e.g. `fuchsia.logger.LogSink`. If path is not set, the
    /// protocol will be installed in a target component's namespace at
    /// `/svc/{name}`.
    1: name fuchsia.component.name;

    /// A rename of the capability, which can be set when routing to another
    /// component. This field is optional.
    2: as fuchsia.component.name;

    /// For information on this type, see
    /// https://fuchsia.dev/go/components/declaration#DependencyType.
    /// This field is optional and defaults to `STRONG`.
    3: type fuchsia.component.decl.DependencyType;

    /// Override the path in which the protocol is installed. Instead of
    /// `/svc/{name}`, this value will be used. Path should begin with a
    /// leading slash and omit a trailing slash, e.g.
    /// `/foo/fuchsia.logger.LogSink`. This field is optional.
    4: path string:fuchsia.component.MAX_PATH_LENGTH;

    /// Optional. Cannot be set to `SameAsTarget` if `to` contains a local
    /// component.
    @available(added=10)
    5: availability fuchsia.component.decl.Availability;
};

/// A directory capability.
type Directory = table {
    /// The name of the capability. This is not the path of the directory.
    /// Instead it is a name used for routing.
    1: name fuchsia.component.name;

    /// A rename of the capability, which can be set when routing to another
    /// component. This field is optional.
    2: as fuchsia.component.name;

    /// For information on this type, see
    /// https://fuchsia.dev/go/components/declaration#DependencyType.
    /// This field is optional and defaults to `STRONG`.
    3: type fuchsia.component.decl.DependencyType;

    /// The subdirectory of this directory to offer instead of the root. For
    /// example, if you set `bar/baz` as the subdir of `foo`, then `bar/baz`
    /// will be the root of the target's `foo`. This field is optional.
    4: subdir string:fuchsia.component.MAX_PATH_LENGTH;

    /// The maximum rights that can be set by a component using this directory.
    /// This field is required if it is being routed to a local component,
    /// otherwise, it is optional.
    5: rights fuchsia.io.Rights;

    /// The path in which to install the directory. The path should have a
    /// leading slash but no trailing slash, e.g. `/config/data`. This field
    /// is required.
    6: path string:fuchsia.component.MAX_PATH_LENGTH;

    /// Optional. Cannot be set to `SameAsTarget` if `to` contains a local
    /// component.
    @available(added=10)
    7: availability fuchsia.component.decl.Availability;
};

/// A storage capability
type Storage = table {
    /// The name of the capability. This is not the path of the directory.
    /// Instead it is a name used for routing.
    1: name fuchsia.component.name;

    /// A rename of the capability, which can be set when routing to another
    /// component. This field is optional.
    2: as fuchsia.component.name;

    /// The path in which to install the directory. The path should have a
    /// leading slash but no trailing slash, e.g. `/config/data`. This field
    /// is required.
    3: path fuchsia.component.name;

    /// Optional. Cannot be set to `SameAsTarget` if `to` contains a local
    /// component.
    @available(added=10)
    4: availability fuchsia.component.decl.Availability;
};

/// A service capability
type Service = table {
    /// The name of the capability. This is usually the name of the FIDL
    /// service, e.g. `fuchsia.echo.EchoService`. If path is not set, the
    /// service will be installed in a target component's namespace at
    /// `/svc/{name}`.
    1: name fuchsia.component.name;

    /// A rename of the capability, which can be set when routing to another
    /// component. This field is optional.
    2: as fuchsia.component.name;

    /// Override the path in which the service is installed. Instead of
    /// `/svc/{name}`, this value will be used. Path should begin with a
    /// leading slash and omit a trailing slash, e.g.
    /// `/foo/fuchsia.echo.EchoService`. This field is optional.
    3: path string:fuchsia.component.MAX_PATH_LENGTH;

    /// Optional. Cannot be set to `SameAsTarget` if `to` contains a local
    /// component.
    @available(added=10)
    4: availability fuchsia.component.decl.Availability;
};

/// An event capability
type Event = table {
    /// The name of the capability.
    1: name fuchsia.component.name;

    /// A rename of the capability, which can be set when routing to another
    /// component. This field is optional.
    2: as fuchsia.component.name;

    /// A filter to apply on the event.
    3: filter fuchsia.data.Dictionary;

    /// Optional. Cannot be set to `SameAsTarget` if `to` contains a local
    /// component.
    @available(added=10)
    4: availability fuchsia.component.decl.Availability;
};

/// An event_stream capability
@available(added=9)
type EventStream = table {
    /// The name of the capability.
    1: name fuchsia.component.name;

    /// A rename of the capability, which can be set when routing to another
    // component. This field is optional.
    2: as fuchsia.component.name; // optional

    /// Sets the path in which the event_stream is installed.
    3: path string:fuchsia.component.MAX_PATH_LENGTH;

    /// A filter to apply on the event.
    4: filter fuchsia.data.Dictionary;

    /// A list of objects underneath this component to downscope the event to.
    /// Example: #my_child_component, #my_child_collection.
    5: scope vector<fuchsia.component.decl.Ref>:MAX;
};

/// A configuration capability
@available(added=HEAD)
type Config = table {
    /// The name of the capability.
    1: name fuchsia.component.name;

    /// A rename of the capability, which can be set when routing to another
    /// component. This field is optional.
    2: as fuchsia.component.name;

    /// Optional. Cannot be set to `SameAsTarget` if `to` contains a local
    /// component.
    3: availability fuchsia.component.decl.Availability;
};

/// Properties that may be set on a child when it is added to a realm.
// TODO(https://fxbug.dev/42078374): Consider deprecating this type.
type ChildOptions = table {
    /// For information on this type, see
    /// https://fuchsia.dev/go/components/declaration#StartupMode.
    /// Defaults to `LAZY`.
    1: startup fuchsia.component.decl.StartupMode;

    /// Specify a custom environment for the child to run under.
    2: environment fuchsia.component.name;

    /// For information on this type, see
    /// https://fuchsia.dev/go/components/declaration#OnTerminate.
    /// Defaults to `NONE`.
    3: on_terminate fuchsia.component.decl.OnTerminate;

    /// Structured Configuration overrides to be applied to the child.
    /// Only keys declared by the child component as overridable by parent may
    /// be provided. For information on overrides, see
    /// [fuchsia.component.decl/ConfigOverride].
    @available(added=13)
    4: config_overrides vector<fuchsia.component.decl.ConfigOverride>:MAX;
};

/// Maximum number of entries allowed in one call of `Realm.ReadOnlyDirectory`.
const MAX_DIRECTORY_ENTRIES uint32 = 1024;

/// The contents of a directory that should be provided by the realm builder
/// server.
type DirectoryContents = resource struct {
    entries vector<DirectoryEntry>:MAX_DIRECTORY_ENTRIES;
};

/// An entry in a directory.
type DirectoryEntry = resource struct {
    /// The path to the file. Valid examples include `foo.txt` and
    /// `foo/bar.json`.
    file_path fuchsia.component.name;

    /// The contents of the file.
    file_contents fuchsia.mem.Buffer;
};

closed protocol Realm {
    /// Adds a component to the realm.
    ///
    /// The `url` can be in one of the following formats:
    ///
    /// - an absolute component URL (such as,
    ///   "fuchsia-pkg://fuchsia.com/some-package#meta/some-component.cm")
    /// - a relative path component URL to a subpackaged component (like,
    ///   "some-subpackage#meta/subpackaged-component.cm"); or
    /// - a relative fragment-only URL (like, `#meta/other-component.cm`;
    ///   see https://fuchsia.dev/fuchsia-src/reference/components/url#relative-fragment-only)
    ///   indicating the path to a component manifest in the `pkg_dir` supplied
    ///   to `RealmBuilderFactory::Create*()`.
    ///
    /// The realm builder client typically passes a handle to its own `/pkg`
    /// directory, and bundles the `other-component` into the same package.
    ///
    /// Of the three URL types, _only_ component declarations added via the
    /// fragment-only URL can be modified, via
    /// `GetComponentDecl`/`ReplaceComponentDecl` because realm builder actually
    /// performs its own component resolution from the component's manifest and
    /// files bundled in the provided `pkg_dir` (typically from the package
    /// shared by the realm builder client component and the components added
    /// via fragment-only URL).
    ///
    /// Errors:
    /// - `CHILD_ALREADY_EXISTS`: this realm already contains a child with the
    ///   given name.
    /// - `INVALID_MANIFEST_EXTENSION`: `url` does not end with `.cm`
    /// - `DECL_NOT_FOUND`: The test package does not contain the component
    ///   declaration referenced by a fragment-only component URL.
    /// - `DECL_READ_ERROR`: Encountered an I/O error when attempting to read a
    ///   component declaration referenced by a fragment-only component URL from
    ///   the test package.
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict AddChild(struct {
        /// The name of the child that is being added.
        name fuchsia.component.child_name;

        /// The component's URL.
        url fuchsia.url.Url;

        /// Additional properties for the child.
        options ChildOptions;
    }) -> () error RealmBuilderError;

    @available(removed=12)
    strict AddLegacyChild(struct {
        /// The name of the child that is being added.
        name fuchsia.component.child_name;

        /// The component's legacy URL (commonly ends with `.cmx`).
        legacy_url fuchsia.url.Url;

        /// Additional properties for the child.
        options ChildOptions;
    }) -> () error RealmBuilderError;

    /// Adds a component to this realm whose declaration is set to `decl`. When
    /// launched, the component will share the test package as its package
    /// directory, and may access any resources from it.
    ///
    /// Errors:
    /// - `CHILD_ALREADY_EXISTS`: this realm already contains a child with the
    ///   given name.
    /// - `INVALID_COMPONENT_DECL`: `decl` failed validation.
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict AddChildFromDecl(struct {
        /// The name of the child that is being added.
        name fuchsia.component.child_name;

        /// The component's declaration.
        decl fuchsia.component.decl.Component;

        /// Additional properties for the child.
        options ChildOptions;
    }) -> () error RealmBuilderError;

    /// Adds a component to the realm whose implementation will be provided by
    /// the client. When this component should be started, the runner channel
    /// passed into `Build` will receive a start request for a component whose
    /// `ProgramDecl` contains the moniker from the root of the
    /// constructed realm for the child that is to be run under the `program`
    /// key `LOCAL_COMPONENT_NAME`.
    ///
    /// Errors:
    /// - `CHILD_ALREADY_EXISTS`: this realm already contains a child with the
    ///   given name.
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict AddLocalChild(struct {
        /// The name of the child that is being added.
        name fuchsia.component.child_name;

        /// Additional properties for the child.
        options ChildOptions;
    }) -> () error RealmBuilderError;

    /// Adds a child realm which can be built with the client end of
    /// `child_realm`.
    ///
    /// Errors:
    /// - `CHILD_ALREADY_EXISTS`: this realm already contains a child with the
    ///   given name.
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict AddChildRealm(resource struct {
        /// The name of the child realm that is being added.
        name fuchsia.component.name;

        /// Additional properties for the child.
        options ChildOptions;

        /// The server end of the `Realm` channel that will be used to build the
        /// sub-realm.
        child_realm server_end:Realm;
    }) -> () error RealmBuilderError;

    /// Returns the component decl for the given component. `name` must refer to
    /// a component that is one of the following:
    ///
    /// - A component with a local implementation
    /// - A legacy component
    /// - A component added with a fragment-only URL (typically, components
    ///   bundled in the same package as the realm builder client, sharing the
    ///   same `/pkg` directory, for example, `#meta/other-component.cm`; see
    ///   https://fuchsia.dev/fuchsia-src/reference/components/url#relative-fragment-only)
    /// - An automatically generated realm (ex: the root)
    ///
    /// Errors:
    /// - `NO_SUCH_CHILD`: This realm does not contain a child with the given
    ///   name.
    /// - `CHILD_DECL_NOT_VISIBLE`: The component decl cannot be fetched for
    ///   the referenced child, because the child was added to the realm using
    ///   a modern (not legacy) absolute URL or subpackaged component's relative
    ///   path URL.
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict GetComponentDecl(struct {
        /// The name of the component whose declaration is being retrieved.
        name fuchsia.component.child_name;
    }) -> (struct {
        component_decl fuchsia.component.decl.Component;
    }) error RealmBuilderError;

    /// Replaces the component decl for the given component. `name` must
    /// refer to a component that is one of the following:
    ///
    /// - A component with a local implementation
    /// - A legacy component
    /// - A component added with a fragment-only URL (typically, components
    ///   bundled in the same package as the realm builder client, sharing the
    ///   same `/pkg` directory, for example, `#meta/other-component.cm`; see
    ///   https://fuchsia.dev/fuchsia-src/reference/components/url#relative-fragment-only)
    /// - An automatically generated realm (ex: the root)
    ///
    /// Errors:
    /// - `NO_SUCH_CHILD`: This realm does not contain a child with the given
    ///   name.
    /// - `CHILD_ALREADY_EXISTS`: The component whose decl is being replaced has
    ///   had a child added to it through realm builder with the same name as an
    ///   element in `component_decl.children`.
    /// - `CHILD_DECL_NOT_VISIBLE`: The component decl cannot be manipulated for
    ///   the referenced child, because the child was added to the realm using
    ///   an absolute (not relative) and modern (not legacy) URL.
    /// - `INVALID_COMPONENT_DECL`: `component_decl` failed validation.
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict ReplaceComponentDecl(struct {
        /// The name of the component whose declaration is being replaced.
        name fuchsia.component.child_name;

        /// The new component declaration for `name`.
        component_decl fuchsia.component.decl.Component;
    }) -> () error RealmBuilderError;

    /// Returns the component decl for this realm.
    ///
    /// Errors:
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict GetRealmDecl() -> (struct {
        component_decl fuchsia.component.decl.Component;
    }) error RealmBuilderError;

    /// Replaces the component decl for this realm.
    ///
    /// Errors:
    /// - `INVALID_COMPONENT_DECL`: `component_decl` failed validation.
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict ReplaceRealmDecl(struct {
        /// The new component declaration for this realm.
        component_decl fuchsia.component.decl.Component;
    }) -> () error RealmBuilderError;

    /// Mutates component manifests in the realm such that every component in
    /// `to` will have a valid capability route for each item in `capabilities`
    /// provided by `from`.
    ///
    /// Errors:
    /// - `NO_SUCH_SOURCE`: `from` references a non-existent child.
    /// - `NO_SUCH_TARGET`: `to` references a non-existent child.
    /// - `CAPABILITIES_EMPTY`: `capabilities` is empty.
    /// - `TARGETS_EMPTY`: `to` is empty.
    /// - `SOURCE_AND_TARGET_MATCH`: `from` is equal to one of the elements in
    ///   `to`.
    /// - `INVALID_COMPONENT_DECL`: The requested route caused one of the
    ///   involved manifests to fail validation.
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict AddRoute(struct {
        /// The capabilities that are to be routed.
        capabilities vector<Capability>:MAX;

        /// The location where the elements of `capabilities` are available.
        from fuchsia.component.decl.Ref;

        /// The locations that should be able to access `capabilities`.
        to vector<fuchsia.component.decl.Ref>:MAX;
    }) -> () error RealmBuilderError;

    /// Offers a directory capability to a component in this realm. The
    /// directory will be read-only (i.e. have `r*` rights), and will have the
    /// contents described in `directory_contents`.
    ///
    /// Errors:
    /// - `NO_SUCH_TARGET`: `offer-to` references a non-existent child.
    /// - `BUILD_ALREADY_CALLED`: The `Builder.Build` function has been called
    ///   for this realm, and thus this `Realm` channel can no longer be used.
    strict ReadOnlyDirectory(resource struct {
        /// The name of the directory capability.
        name fuchsia.component.name;

        /// The target that this directory will be offered to.
        to vector<fuchsia.component.decl.Ref>:MAX;

        /// The contents of the directory.
        directory_contents DirectoryContents;
    }) -> () error RealmBuilderError;

    /// Load any packaged configuration for `name` before using values provided to
    /// the builder.
    ///
    /// Allows calling `SetConfigValue` to override packaged configuration.
    @available(added=9)
    strict InitMutableConfigFromPackage(struct {
        name fuchsia.component.name;
    }) -> () error RealmBuilderError;

    /// Use only values provided to the builder for `name`'s configuration.
    ///
    /// Allows calling `SetConfigValue` to provide configuration.
    @available(added=9)
    strict InitMutableConfigToEmpty(struct {
        name fuchsia.component.name;
    }) -> () error RealmBuilderError;

    @available(removed=12)
    strict ReplaceConfigValue(struct {
        name fuchsia.component.name;
        key fuchsia.component.decl.ConfigKey;
        value fuchsia.component.config.ValueSpec;
    }) -> () error RealmBuilderError;

    /// Add a capability to the realm.
    @available(added=HEAD)
    strict AddCapability(struct {
        capability fuchsia.component.decl.Capability;
    }) -> () error RealmBuilderError;

    /// Sets the configuration value for a field specified by `key`.
    /// The component specified must have a config schema with this field.
    /// The value must conform to all constraints as defined by the schema.
    ///
    /// This method must be called after either `InitMutableConfigFromPackage` or
    /// `InitMutableConfigToEmpty`.
    ///
    /// Errors:
    /// - `NO_CONFIG_SCHEMA`: component does not have a config schema
    /// - `NO_SUCH_CONFIG_FIELD`: `key` could not be found in component's config schema
    /// - `CONFIG_VALUE_INVALID`: `value` does not meet config schema constraints
    @available(added=13)
    strict SetConfigValue(struct {
        /// The name of the component whose config value is being replaced.
        name fuchsia.component.name;

        /// The key of the config field whose value is being replaced.
        key fuchsia.component.decl.ConfigKey;

        /// The config value being replaced.
        value fuchsia.component.decl.ConfigValueSpec;
    }) -> () error RealmBuilderError;

    // replaced by ABI-compatible type above
    @available(added=9, replaced=13)
    strict SetConfigValue(struct {
        /// The name of the component whose config value is being replaced.
        name fuchsia.component.name;

        /// The key of the config field whose value is being replaced.
        key fuchsia.component.decl.ConfigKey;

        /// The config value being replaced.
        value fuchsia.component.config.ValueSpec;
    }) -> () error RealmBuilderError;
};