81 lines
1.9 KiB
Markdown
81 lines
1.9 KiB
Markdown
# Snapshot Tests
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The `.fine` files in this directory and its descendants are processed
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by `build.rs` into a series of snapshot-tests. The various test
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assertions are specified by `@` directives in comments in the file.
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e.g., a test might look like this:
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```fine
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// @concrete:
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// | File
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// | ExpressionStatement
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// | BinaryExpression
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// | BinaryExpression
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// | LiteralExpression
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// | Number:'"1"'
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// | Star:'"*"'
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// | LiteralExpression
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// | Number:'"2"'
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// | Plus:'"+"'
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// | BinaryExpression
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// | UnaryExpression
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// | Minus:'"-"'
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// | LiteralExpression
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// | Number:'"3"'
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// | Star:'"*"'
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// | LiteralExpression
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// | Number:'"4"'
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// | Semicolon:'";"'
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//
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1 * 2 + -3 * 4;
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// @type: 532 f64
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```
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## Assertions
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The various assertions are as follows:
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- The `// @ignore` directive marks the test as ignored.
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- The `// @concrete:` assertion says that the following lines
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(prefixed with `// | `, as above) describe the concrete syntax tree
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of the file after parsing.
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e.g.:
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```fine
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// @concrete:
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// | File
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// | ExpressionStatement
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// | LiteralExpression
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// | String:'"\"Hello world\""'
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// | Semicolon:'";"'
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//
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"Hello world";
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```
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- The `// @type:` assertion says that the type of the tree at the
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given point will match the given type. `@type` assertions usually go
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after the contents of the file to make the probe points more stable
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in the face of new assertions and whatnot.
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e.g.:
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```fine
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"Hello world!"
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// @type: 2 string
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```
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- The `// @type-error:` assertion says that the type of the tree at
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the given point should be an error, and that the error message
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provided should be among the generated errors. (Like `@type`, these
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usually go after the code, for stability.)
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e.g.:
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```fine
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- "twenty five";
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// @type-error: 0 cannot apply unary operator '-' to value of type string
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```
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