chore: markdown warnings (#11302)

* rename warnings.js to warnings-tmp.js

* start porting warnings

* centralise stuff

* finish porting warnings

* tidy up

* get messages into JSDoc annotations

* prettier

* lint

Author: Rich-Harris

.prettierignore

@@ -4,6 +4,7 @@ packages/**/npm/**/*
 packages/**/config/*.js
 packages/svelte/messages/**/*.md
 packages/svelte/src/compiler/errors.js
+packages/svelte/src/compiler/warnings.js
 packages/svelte/tests/**/*.svelte
 packages/svelte/tests/**/_expected*
 packages/svelte/tests/**/_actual*

packages/svelte/messages/compile-warnings/a11y.md

@@ -0,0 +1,171 @@
+## a11y_aria_attributes
+
+<%name%> should not have aria-* attributes
+
+## a11y_unknown_aria_attribute
+
+Unknown aria attribute 'aria-%attribute%'
+
+## a11y_unknown_aria_attribute_suggestion
+
+Unknown aria attribute 'aria-%attribute%'. Did you mean '%suggestion%'?
+
+## a11y_hidden
+
+<%name%> element should not be hidden
+
+## a11y_incorrect_aria_attribute_type_boolean
+
+The value of '%attribute%' must be either 'true' or 'false'
+
+## a11y_incorrect_aria_attribute_type_integer
+
+The value of '%attribute%' must be an integer
+
+## a11y_incorrect_aria_attribute_type_id
+
+The value of '%attribute%' must be a string that represents a DOM element ID
+
+## a11y_incorrect_aria_attribute_type_idlist
+
+The value of '%attribute%' must be a space-separated list of strings that represent DOM element IDs
+
+## a11y_incorrect_aria_attribute_type_tristate
+
+The value of '%attribute%' must be exactly one of true, false, or mixed
+
+## a11y_incorrect_aria_attribute_type_token
+
+The value of '%attribute%' must be exactly one of %values%
+
+## a11y_incorrect_aria_attribute_type_tokenlist
+
+The value of '%attribute%' must be a space-separated list of one or more of %values%
+
+## a11y_incorrect_aria_attribute_type
+
+The value of '%attribute%' must be of type %type%
+
+## a11y_aria_activedescendant_has_tabindex
+
+Elements with attribute aria-activedescendant should have tabindex value
+
+## a11y_misplaced_role
+
+<%name%> should not have role attribute
+
+## a11y_no_abstract_role
+
+Abstract role '%role%' is forbidden
+
+## a11y_unknown_role
+
+Unknown role '%role%'
+
+## a11y_unknown_role_suggestion
+
+Unknown role '%role%'. Did you mean '%suggestion%'?
+
+## a11y_no_redundant_roles
+
+Redundant role '%role%'
+
+## a11y_role_has_required_aria_props
+
+Elements with the ARIA role "%role%" must have the following attributes defined: %props%
+
+## a11y_interactive_supports_focus
+
+Elements with the '%role%' interactive role must have a tabindex value.
+
+## a11y_no_interactive_element_to_noninteractive_role
+
+<%element%> cannot have role '%role%'
+
+## a11y_no_noninteractive_element_to_interactive_role
+
+Non-interactive element <%element%> cannot have interactive role '%role%'
+
+## a11y_accesskey
+
+Avoid using accesskey
+
+## a11y_autofocus
+
+Avoid using autofocus
+
+## a11y_misplaced_scope
+
+The scope attribute should only be used with <th> elements
+
+## a11y_positive_tabindex
+
+Avoid tabindex values above zero
+
+## a11y_click_events_have_key_events
+
+Visible, non-interactive elements with a click event must be accompanied by a keyboard event handler. Consider whether an interactive element such as <button type="button"> or <a> might be more appropriate. See https://svelte.dev/docs/accessibility-warnings#a11y-click-events-have-key-events for more details.
+
+## a11y_no_noninteractive_tabindex
+
+noninteractive element cannot have nonnegative tabIndex value
+
+## a11y_role_supports_aria_props
+
+The attribute '%attribute%' is not supported by the role '%role%'
+
+## a11y_role_supports_aria_props_implicit
+
+The attribute '%attribute%' is not supported by the role '%role%'. This role is implicit on the element <%name%>
+
+## a11y_no_noninteractive_element_interactions
+
+Non-interactive element <%element%> should not be assigned mouse or keyboard event listeners.
+
+## a11y_no_static_element_interactions
+
+<%element%> with a %handler% handler must have an ARIA role
+
+## a11y_invalid_attribute
+
+'%href_value%' is not a valid %href_attribute% attribute
+
+## a11y_missing_attribute
+
+<%name%> element should have %article% %sequence% attribute
+
+## a11y_autocomplete_valid
+
+The value '%value%' is not supported by the attribute 'autocomplete' on element <input type="%type%">
+
+## a11y_img_redundant_alt
+
+Screenreaders already announce <img> elements as an image.
+
+## a11y_label_has_associated_control
+
+A form label must be associated with a control.
+
+## a11y_media_has_caption
+
+<video> elements must have a <track kind="captions">
+
+## a11y_distracting_elements
+
+Avoid <%name%> elements
+
+## a11y_figcaption_parent
+
+`<figcaption>` must be an immediate child of `<figure>`
+
+## a11y_figcaption_index
+
+`<figcaption>` must be first or last child of `<figure>`
+
+## a11y_mouse_events_have_key_events
+
+'%event%' event must be accompanied by '%accompanied_by%' event
+
+## a11y_missing_content
+
+<%name%> element should have child content

packages/svelte/messages/compile-warnings/attributes.md

@@ -0,0 +1,15 @@
+## avoid_is
+
+The "is" attribute is not supported cross-browser and should be avoided
+
+## global_event_reference
+
+You are referencing globalThis.%name%. Did you forget to declare a variable with that name?
+
+## illegal_attribute_character
+
+Attributes should not contain ':' characters to prevent ambiguity with Svelte directives
+
+## invalid_html_attribute
+
+'%wrong%' is not a valid HTML attribute. Did you mean '%right%'?

packages/svelte/messages/compile-warnings/block.md

@@ -0,0 +1,3 @@
+## empty_block
+
+Empty block

packages/svelte/messages/compile-warnings/components.md

@@ -0,0 +1,3 @@
+## component_name_lowercase
+
+<%name%> will be treated as an HTML element unless it begins with a capital letter

packages/svelte/messages/compile-warnings/css.md

@@ -0,0 +1,3 @@
+## css_unused_selector
+
+Unused CSS selector "%name%"

packages/svelte/messages/compile-warnings/legacy.md

@@ -0,0 +1,19 @@
+## no_reactive_declaration
+
+Reactive declarations only exist at the top level of the instance script
+
+## module_script_reactive_declaration
+
+All dependencies of the reactive declaration are declared in a module script and will not be reactive
+
+## unused_export_let
+
+Component has unused export property '%name%'. If it is for external reference only, please consider using `export const %name%`
+
+## deprecated_slot_element
+
+Using <slot> to render parent content is deprecated. Use {@render ...} tags instead.
+
+## deprecated_event_handler
+
+Using on:%name% to listen to the %name% event is is deprecated. Use the event attribute on%name% instead.

packages/svelte/messages/compile-warnings/misc.md

@@ -0,0 +1,3 @@
+## invalid_self_closing_tag
+
+Self-closing HTML tags for non-void elements are ambiguous — use <%name% ...></%name%> rather than <%name% ... />

packages/svelte/messages/compile-warnings/options.md

@@ -0,0 +1,3 @@
+## missing_custom_element_compile_option
+
+The 'customElement' option is used when generating a custom element. Did you forget the 'customElement: true' compile option?

packages/svelte/messages/compile-warnings/performance.md

@@ -0,0 +1,7 @@
+## avoid_inline_class
+
+Avoid 'new class' — instead, declare the class at the top level scope
+
+## avoid_nested_class
+
+Avoid declaring classes below the top level scope