Import tests from unofficial testing repo

README.md

@@ -1,6 +1,6 @@
 # Source Map Tests
 
-This repository holds testing discussions for the the Source Map debugging format. Specifically, we're looking to encourage discussion around:
+This repository holds testing discussions and tests for the the Source Map debugging format. Specifically, we're looking to encourage discussion around:
 
 - Manual and automated testing strategies for Source Maps
 - Gathering a list of Soure Map generators and consumers
@@ -9,3 +9,151 @@ This repository holds testing discussions for the the Source Map debugging forma
 Open discussion happens in the [GitHub issues](https://github.com/source-map/source-map-tests/issues).
 
 Source Map spec: https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit?pli=1#
+
+## Test cases
+
+These test cases are still a work-in-progress 🚧.
+
+#### Running the tests
+
+How to run in WebKit:
+  * Check out [WebKit](https://github.com/WebKit/WebKit/)
+  * `cd` to the checked out WebKit directory.
+  * Run `git am <this-repo>/webkit/0001-Add-harness-for-source-maps-spec-tests.patch`
+  * Run `Tools/Scripts/build-webkit` (depending on the platform you may need to pass `--gtk` or other flags)
+  * Run `Tools/Scripts/run-webkit-tests LayoutTests/inspector/model/source-map-spec.html` (again, you may need `--gtk` on Linux)
+
+For Firefox, see the Mozilla [source-map](https://github.com/mozilla/source-map) library:
+  * There is a [branch](https://github.com/takikawa/source-map/tree/add-spec-tests) for adding the spec tests to the package.
+
+### Goals of tests
+
+* Thoroughly test all aspects of the source maps spec that can be tested.
+* Strictly follow the spec when determining test behavior.
+
+### Test coverage
+
+#### Core spec
+
+* Encoding
+  - [ ] Source map must be a valid JSON document.
+  - Base64 VLQ
+    * VLQs should decode correctly
+      - [X] A VLQ with a non-base64 character will fail to decode.
+      - [ ] A VLQ with one digit and no continuation digits should decode.
+      - [ ] A negative VLQ with the sign bit set to 1 should decode.
+      - [ ] A VLQ with non-zero continuation bits (and more than one digit) should decode.
+      - [X] A VLQ with a non-zero continuation bit with no further digits should fail to decode.
+      - [ ] A VLQ should decode with the correct order of digits (least to most significant).
+      - [x] A long VLQ with many trailing zero digits will decode.
+    * [x] A VLQ exceeding the 32-bit size limit is invalid (note: the spec is unclear on the details of this limit)
+    * [x] A VLQ at exactly the 32-bit size limit should be decoded (positive and negative).
+* Basic format
+  - `version` field
+    * [X] Must be present
+    * [X] Must be a number
+    * [X] Must be 3
+  - `file` field
+    * [ ] Optional, allow missing
+    * [ ] Must be a string? (spec is not clear)
+  - `sourceRoot` field
+    * [ ] Optional, allow missing
+    * [ ] Must be a string? (spec is not clear)
+  - `sources` field
+    * [X] Must be present
+    * [X] Must be an array
+    * [X] Array elements must be `null` or a string
+  - `sourcesContent` field
+    * [X] Must be present
+    * [X] Must be an array
+    * [X] Array elements must be `null` or a string
+  - `names` field
+    * [X] Must be present (note: the spec implies this but implementations may not agree)
+    * [X] Must be an array
+    * [X] Array elements must be strings
+  - `mappings` field
+    * [X] Must be present
+    * [X] Must be a string
+    * [ ] Empty string is valid
+  - `ignoreList` field
+    * [ ] Optional, allow missing
+    * [ ] Must be an array
+    * [ ] Array elements must be numbers
+    * [ ] Elements must not be out of bounds for the `sources` list
+  - [X] Extra unrecognized fields are allowed
+* Index maps
+  - ? Must be mutually exclusive with non-index map?
+  - `file` field
+    * [ ] Optional, allow missing
+    * [ ] Must be a string? (spec is not clear)
+  - `sections` field
+    * [X] Must be present
+    * [X] Must be an array
+    * [ ] An empty sections array is valid
+    * [X] Array elements are valid section objects
+      - `offset` field
+        * [X] Must be present
+        * `line` field
+          - [X] Must be present
+          - [X] Must be a number
+        * `column` field
+          - [X] Must be present
+          - [X] Must be a number
+      - `map` field
+        * [X] Must be present
+        * [X] Must be an object
+        * [ ] Must be a valid source map
+    - [X] Sections are in order (the spec is not 100% clear, but assumption is increasing numeric order, may need subtests)
+    - [X] Sections are non-overlapping (the definition of overlap is not clear, may need subtests)
+* Mappings format
+  - [X] Each line is separated by ";"
+  - [X] A line may consist of zero segments (e.g., ";;")
+  - [X] Each line consists only of segments separated by ","
+  - [X] Must have greater than zero fields (note: many implementations don't check)
+  - [X] Must have 1, 4, or 5 fields
+  - [X] The source index must not be out of bounds of the sources array
+  - [X] The name index must not be out of bounds of the names array
+  - Absolute VLQ values must be non-negative
+    * [X] The column must be non-negative
+    * [X] The source index must be non-negative
+    * [X] The original line must be non-negative
+    * [X] The original column must be non-negative
+    * [X] The name index must be non-negative
+  - Relative VLQ values must be non-negative after adding to previous value
+    * [X] The column must be non-negative
+    * [X] The source index must be non-negative
+    * [X] The original line must be non-negative
+    * [X] The original column must be non-negative
+    * [X] The name index must be non-negative
+* Ignore list
+  - [X] An ignore list is optional, may be missing
+  - [X] An ignore list can't be a non-array value
+    * [X] An ignore list can be empty
+    * [X] An ignore list entry must be a number
+    * [X] An ignore list entry cannot be out-of-bounds of the sources array
+  - [X] Ignore list entries are detected and are present
+  - [X] Items not specified in the ignore list don't show up as ignored
+* Mappings semantics
+  - [ ] A source map with no mappings does not map any position.
+  - [ ] A single field segment gets mapped to the correct line and column.
+  - [X] A four field segment gets mapped to the correct line and column.
+  - [X] A five field segment gets mapped to the correct line and column.
+  - [X] When a name is present in a segment, it is correctly mapped.
+  - [X] When a source is present in a segment, it is correctly mapped.
+  - [ ] The second occurence of a field segment in a line is mapped relative to the previous one.
+  - [ ] When a new line starts, the generated column field resets to zero rather than being relative to the previous line.
+  - [ ] For fields other than the generated column, a segment field that has occured once in a previous line is mapped relatively when it occurs in the next line.
+  - [ ] Ensure that a transitive source map mapping works as expected
+  - Index maps are correctly used in mappings
+    * [ ] An index map with one sub-map will map correctly.
+    * [X] An index map with multiple sub-maps will map correctly, with appropriate offsets for the second and later sub-maps.
+* Resolution of sources
+  - [ ] When `sourceRoot` is provided, it is prepended to any `sources` entries and will be mapped with the full URL.
+  - [ ] If the source URL is an absolute URL, it is resolved as an absolute URL.
+  - [ ] If the source  URL is a relative URL, it is resolved relative to the source map path.
+* Wasm support
+  - [ ] Create versions of the tests that use a Wasm source.
+
+### Scopes Proposal
+
+TODO